Fact-checked by Grok 2 weeks ago

Saliva testing

Saliva testing, also known as salivary diagnostics, is a non-invasive analytical method that examines human saliva—a complex biological fluid secreted by the major and minor salivary glands—to detect and quantify biomarkers such as proteins, hormones, enzymes, nucleic acids, electrolytes, and microbial components for the diagnosis, monitoring, and screening of oral and systemic diseases.^[1] This approach leverages saliva's composition, which includes over 1,000 proteins and mirrors approximately 20-30% of blood-based proteins, allowing it to reflect physiological states and pathological changes without the need for invasive procedures like venipuncture.^[2] Daily saliva production in humans averages about 600-1,000 mL, with 99% consisting of water and the remainder comprising bioactive molecules that can indicate conditions ranging from local oral pathologies to broader systemic disorders.^[2] The advantages of saliva testing are particularly notable in clinical settings, where it offers a painless, cost-effective, and patient-compliant alternative to traditional blood or tissue sampling, facilitating frequent and point-of-care applications such as mass screenings and home-based monitoring.^[3] Unlike blood draws, saliva collection is straightforward—often involving simple spitting into a tube—and poses minimal risk of infection or discomfort, making it ideal for vulnerable populations like children, the elderly, or those in remote areas.^[1] Technological advancements, including enzyme-linked immunosorbent assays (ELISA), polymerase chain reaction (PCR), microfluidics, and omics technologies (e.g., proteomics and genomics), have propelled its evolution, particularly since the late 20th century, transforming it from a niche tool for oral health assessment into a versatile platform for personalized medicine.^[1] Key applications of saliva testing span dentistry and medicine, with promising and researched uses in detecting oral conditions like dental caries (via biomarkers such as histatin and statherin), periodontal disease (e.g., matrix metalloproteinase-8 [MMP-8] and interleukin-1β [IL-1β]), and oral cancer (e.g., microRNAs like miR-31 and cytokeratins).^[1] In systemic health, it aids in identifying diabetes through elevated salivary glucose levels that correlate with blood glucose, cardiovascular diseases via C-reactive protein (CRP) and alpha-amylase, various cancers (e.g., pancreatic via mRNA markers like KRAS), and infectious diseases including HIV, hepatitis, and SARS-CoV-2 through viral antibodies or RNA.^[2] Hormonal assessments, such as cortisol for stress and adrenal function, further highlight its utility in endocrinology and mental health monitoring.^[3] Despite its promise, saliva testing faces challenges including biomarker variability influenced by factors like age, diet, medications, and circadian rhythms, as well as lower analyte concentrations compared to blood, which necessitates sensitive detection methods and standardized protocols for reliable results. Additionally, as of 2025, regulatory approvals like FDA clearance remain limited for many applications beyond HIV detection, hindering broader clinical integration.^[1] Ongoing research emphasizes biomarker validation, integration with artificial intelligence for data analysis—including 2025 advancements like AI-backed screening for chemotherapy risks—and development of portable biosensors to overcome these hurdles and expand its role in early disease detection and prognostic evaluation.^[2]^[4]

Fundamentals

Collection and Analysis Techniques

Saliva collection and analysis techniques have evolved significantly since the 19th century, when basic methods involved simple expectoration for cytochemical analysis of metabolic conditions like gout and rheumatism.^[5] By the early 20th century, standardized procedures emerged, including the use of Lashley's cup for parotid saliva collection in 1916, enabling more precise glandular-specific sampling.^[5] The mid-20th century saw advancements like radioimmunoassays in the 1960s for cystic fibrosis screening, while the 1980s introduced enzyme-linked immunosorbent assays (ELISA) for hormone detection, and the early 2000s brought commercial point-of-care tests such as OraQuick for HIV.^[6]^[7] Recent decades have featured "salivaomics" initiatives since 2008, cataloging the salivary proteome and integrating microfluidics for portable diagnostics.^[5] Saliva samples are categorized as whole saliva, which is a mixed secretion from major and minor glands combined with oral fluids, or glandular-specific saliva, such as parotid (from the parotid gland, collected via devices like Lashley's cup) and submandibular (from the submandibular gland, often via cannulation).^[8] Whole saliva is commonly used for broad biomarker screening due to its representation of overall oral physiology, while glandular-specific samples allow targeted analysis of individual gland functions.^[8] Collection methods prioritize non-invasiveness and minimal contamination, with typical volumes ranging from 1-5 mL depending on the technique and analyte.^[6] Passive drool involves pooling unstimulated saliva in the mouth for 2-5 minutes, followed by expectoration into a sterile tube, ideal for analytes sensitive to stimulation like cortisol.^[8] Swab-based absorption uses cotton or synthetic swabs placed sublingually or buccally for 1-2 minutes to absorb 0.5-1 mL, then transferred to an extraction tube; this method suits pediatric or low-volume collections but may introduce swab-derived interferents.^[8] Stimulation techniques enhance flow rates to 1-2 mL/min; for example, applying 2% citric acid to the tongue or chewing paraffin gum for 1-3 minutes increases secretion before collection via drool or suction, useful for enzyme assays but altering pH-sensitive biomarkers.^[8] Post-collection handling protocols emphasize stability and purity: samples should be centrifuged at 3,000 rpm for 15 minutes to remove debris, with supernatants aliquoted to avoid freeze-thaw cycles.^[6] Contamination is minimized by instructing donors to abstain from food, drink (except water), and oral hygiene for 1 hour prior, using protease inhibitors if needed, and employing sterile, DNA/RNA-free materials.^[6] Short-term storage at 4°C lasts 3-6 hours, while long-term preservation at -80°C maintains integrity for up to 1 year for most analytes; volumes under 1 mL require cryogenic vials to prevent loss.^[6] Diurnal variations in flow and composition necessitate standardized collection times, typically morning.^[6] Laboratory analysis employs diverse techniques tailored to target molecules. Immunoassays like ELISA detect proteins and antibodies (e.g., HIV via OraQuick) with high sensitivity in 96-well plates, requiring 50-100 μL per well.^[6] Mass spectrometry, often liquid chromatography-tandem mass spectrometry (LC-MS/MS), quantifies metabolites and drugs (e.g., benzodiazepines) at picomolar levels after sample preconcentration.^[6] Polymerase chain reaction (PCR), including quantitative real-time PCR (qRT-PCR), amplifies nucleic acids for pathogen detection (e.g., HPV) from 200-500 μL, with RNA stabilized by RNAlater.^[6] Electrochemical sensors enable point-of-care testing via micropatterned electrodes measuring ions or biomarkers like uric acid in real-time, processing 10-50 μL with results in minutes.^[6] Modern microfluidic devices integrate these on chips, automating mixing and detection for portable saliva analysis of multiple biomarkers simultaneously.^[9]

Physiologic Basis

Saliva is a complex biological fluid primarily composed of approximately 99% water, along with electrolytes such as sodium, potassium, calcium, and bicarbonate, enzymes like amylase, proteins including mucins and immunoglobulins, hormones, and various metabolites.^[10] These components originate from the major salivary glands (parotid, submandibular, and sublingual) as well as minor glands and gingival crevicular fluid, contributing to its role as a diagnostic matrix.^[11] Biomarkers enter saliva from the bloodstream through several mechanisms, including passive diffusion for small, lipophilic molecules such as steroid hormones like cortisol, active transport via ion channels or transporters in salivary acinar cells, and ultrafiltration across the basal lamina of glandular epithelium for low-molecular-weight substances.^[3] Additionally, certain biomarkers like secretory immunoglobulin A (IgA) are produced locally by plasma cells in the salivary glands and oral mucosa, independent of systemic circulation.^[12] These transfer processes allow saliva to reflect systemic physiological states while incorporating site-specific immune factors. Salivary biomarker concentrations often correlate closely with plasma levels, particularly for unbound, bioactive fractions, as seen in equilibrium models where free cortisol in saliva mirrors the unbound fraction in serum due to passive diffusion across lipid membranes.^[13] This relationship holds for many analytes, enabling saliva to serve as a non-invasive proxy for plasma free hormone and metabolite levels without interference from binding proteins prevalent in blood.^[14] Several physiologic factors influence biomarker stability and detectability in saliva, including its pH range of 6.2-7.6, which affects enzymatic activity and molecular ionization, and unstimulated flow rate of 0.3-0.4 mL/min, which modulates dilution and clearance of analytes.^[15] Circadian rhythms also play a role, with variations in flow rate and electrolyte concentrations peaking during waking hours and declining nocturnally, potentially altering biomarker profiles over the day.^[16] Compared to blood sampling, saliva testing offers reduced invasiveness, as it requires no needles or venipuncture, facilitating easier collection in diverse settings.^[6] Furthermore, saliva predominantly contains free, unbound analytes that represent the biologically active forms, bypassing the need to account for plasma protein binding and providing a direct measure of functional biomarker levels.^[13]

Clinical Applications

Diagnostic Uses in Endocrinology

Saliva testing plays a key role in endocrinology by providing a non-invasive method to measure unbound, biologically active fractions of hormones, which diffuse from blood into saliva via passive transfer across oral mucosa. This approach is particularly valuable for assessing steroid hormones like cortisol, as it reflects free hormone levels without the need for venipuncture, enabling easier serial sampling in outpatient settings. Established applications focus on diagnosing disorders of the hypothalamic-pituitary-adrenal (HPA) axis, reproductive function, and circadian regulation, with protocols emphasizing timed collections to capture diurnal rhythms. In the diagnosis of Cushing's syndrome, late-night salivary cortisol (LNSC) serves as a first-line screening tool, leveraging the loss of normal diurnal cortisol rhythm in hypercortisolism. A cutoff of 1.7 ng/mL (approximately 4.7 nmol/L) for LNSC demonstrates 98% sensitivity and 100% specificity for detecting Cushing's syndrome in one study of adults.^[17] Normal morning salivary cortisol levels range from 3.1 to 22.4 nmol/L, with elevated late-night values indicating pathologic excess. For Addison's disease and secondary adrenal insufficiency, stimulated salivary cortisol after cosyntropin administration provides diagnostic utility; a post-stimulation cutoff of 12.6 nmol/L yields 85% sensitivity and 90% specificity. These measurements correlate strongly with serum free cortisol, offering a patient-friendly alternative for confirming adrenal hypofunction. Salivary assessment of reproductive hormones aids in evaluating ovulatory function and hypogonadism. In women, salivary progesterone levels exceeding 50 pg/mL during the luteal phase, combined with elevations in salivary estradiol (median follicular phase 2.81 pg/mL), confirm ovulation and support fertility tracking. For men, salivary testosterone levels in the normal range of 93-378 pmol/L help diagnose hypogonadism; values below 195 pmol/L exhibit 100% sensitivity and specificity for identifying deficiency. These assays capture the bioavailable hormone fraction, correlating with serum free testosterone and avoiding binding protein interference. Salivary melatonin measurement evaluates circadian disruptions in sleep disorders, such as delayed sleep-wake phase disorder, by assessing the dim light melatonin onset (DLMO). Typical nighttime salivary melatonin peaks at 30-50 pg/mL, with DLMO defined at 3-5 pg/mL; blunted or phase-shifted profiles indicate dysregulation, correlating with poor sleep quality and guiding chronotherapy. Late-night collections (e.g., 10 PM-2 AM) under dim light conditions ensure accuracy. Clinical protocols in salivary endocrinology often involve dynamic testing, such as the overnight dexamethasone suppression test (ODST), where 1 mg dexamethasone is administered at 11 PM, followed by morning salivary cortisol measurement. Suppression to below 2.0 nmol/L rules out Cushing's, with salivary cortisone offering equivalent diagnostic performance to serum cortisol.^[18] For comprehensive HPA evaluation, multiple samples over 24 hours capture cortisol's pulsatile secretion, while similar timed protocols apply to reproductive and melatonin assessments to map menstrual or circadian cycles.

Detection of Infectious Diseases

Saliva testing has emerged as a valuable tool for detecting viral infections, offering a non-invasive alternative to blood or swab-based methods. For human immunodeficiency virus (HIV), detection can target the p24 antigen or viral RNA in saliva, particularly in advanced disease stages where sensitivity reaches approximately 95%. This approach leverages polymerase chain reaction (PCR) assays to amplify HIV RNA, enabling early identification in oral fluids, though it performs best in individuals with established infection rather than acute phases. Similarly, for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), saliva-based antigen rapid tests have shown sensitivities of 80-90% following post-2020 advancements in immunoassay technology, facilitating point-of-care screening during outbreaks. These tests detect viral nucleocapsid proteins and correlate well with nasopharyngeal results in symptomatic cases, supporting widespread use in community settings. As of 2025, saliva-based PCR tests for SARS-CoV-2 have been authorized for emergency use by the FDA with sensitivities exceeding 90% in symptomatic individuals.^[19] Bacterial infections are also amenable to saliva-based diagnostics through targeted assays for microbial components. Helicobacter pylori, a key pathogen in gastric ulcers, can be identified via urease activity or DNA detection in saliva, with PCR methods achieving sensitivities around 87-88% compared to gastric biopsies. This reflects the bacterium's occasional oral colonization, allowing non-invasive monitoring of infection status. In oral health contexts, pathogens like Porphyromonas gingivalis, associated with periodontitis, are profiled using salivary microbial analysis techniques such as 16S rRNA sequencing, which reveal elevated levels in diseased states and aid in disease staging. These profiling methods provide a snapshot of the oral microbiome, correlating salivary abundance with subgingival plaque findings. Parasitic infections in endemic regions benefit from saliva testing for antigen or DNA detection, though sensitivities vary with parasite load. For Entamoeba histolytica, causing amebiasis, salivary IgA antibody assays or nested PCR for DNA demonstrate reliable identification, with sensitivities of approximately 69% in liver abscess cases.^[20] Malaria antigens, such as Plasmodium falciparum histidine-rich protein 2 (PfHRP2), can be detected in saliva using rapid diagnostic tests, achieving sensitivities of 46-100% depending on parasitemia levels above 10,000 parasites/µL, making it suitable for field screening in resource-limited areas. Beyond direct pathogen detection, saliva testing evaluates immune markers to assess infection dynamics and severity. Salivary IgA serves as a key indicator of mucosal immunity, with elevated levels correlating to protective responses against viral pathogens like SARS-CoV-2, where it neutralizes invaders at entry points and predicts faster viral clearance. Cytokines such as interleukin-6 (IL-6) in saliva reflect inflammation severity, showing significant increases in moderate-to-severe COVID-19 cases and associating with worse outcomes, thus aiding prognostic monitoring. The primary advantages of saliva testing for infectious diseases lie in its non-invasiveness, enabling self-collection without trained personnel, which proved crucial during COVID-19 outbreaks for scaling surveillance. From 2020 to 2025, saliva-based protocols paralleled wastewater monitoring in detecting community transmission, as seen in dormitory studies where both methods identified SARS-CoV-2 RNA trends ahead of clinical cases, enhancing outbreak response in schools and workplaces. This approach reduces biohazard risks and supports high-throughput pooling for population-level screening.

Screening for Oncologic Conditions

Saliva testing has emerged as a non-invasive method for screening oncologic conditions through the detection of tumor-derived biomarkers that leak from systemic circulation into salivary glands via physiologic mechanisms such as passive diffusion and active transport.^[21] For oral cancer, particularly oral squamous cell carcinoma (OSCC), salivary levels of cytokeratin 19 fragment (Cyfra 21-1) are significantly elevated compared to healthy controls, with mean concentrations reaching 22.31 ng/mL in patients versus 4.35 ng/mL in controls.^[22] Using a cutoff of 10.88 ng/mL, salivary Cyfra 21-1 demonstrates 85% sensitivity and 92.5% specificity for OSCC detection, with levels correlating to tumor stage and grade.^[22] Squamous cell carcinoma antigen (SCCA), another marker, shows increased salivary expression in OSCC, aiding diagnosis with 90% sensitivity and 83% specificity when detected via ELISA or proteomics, though individual elevations may be modest (1.4-fold increase).^[21]^[23] Concurrent analysis of Cyfra 21-1 with other markers like tissue polypeptide-specific antigen enhances diagnostic accuracy to 71% sensitivity and 75% specificity.^[23] In pancreatic cancer screening, salivary carbohydrate antigen 19-9 (CA19-9) levels correlate with tumor burden, mirroring serum elevations and supporting early detection in symptomatic patients, though primarily validated as a serum biomarker with salivary applications in multi-fluid diagnostics.^[24] Salivary telomerase activity is detectable in neoplastic processes and has been proposed for pancreatic cancer diagnosis, with expression in malignant tissues indicating potential utility in monitoring progression, despite limited salivary-specific validation.^[25]^[26] For breast cancer, salivary human epidermal growth factor receptor 2 (HER2) protein and RNA levels are measurable via ELISA, with elevations in HER2-positive cases correlating to tumor status and aiding prognostic assessment in up to 20% of patients with amplified HER2.^[27] Estrogen receptor markers, including estradiol, are detectable in saliva of postmenopausal patients, showing altered profiles that distinguish cases from controls and support subtype classification through RNA or protein assays.^[27] General neoplastic markers in saliva include microRNAs such as miR-21, which is upregulated across multiple cancers including oral, breast, and pancreatic, serving as a diagnostic biomarker with high expression linked to tumor progression and poor prognosis.^[28] Proteomic profiles, encompassing altered protein patterns like cytokeratins and growth factors, provide comprehensive signatures for pan-cancer screening, with miR-21 integration enhancing specificity in diverse malignancies.^[29] Screening protocols for high-risk populations increasingly employ multiplex assays that simultaneously detect multiple salivary biomarkers, such as miRNAs and proteins, achieving improved discriminatory power for early oncologic detection.^[30] Post-2020 studies integrating artificial intelligence with these assays analyze complex proteomic and miRNA data to boost sensitivity, enabling predictive models for cancers like oral and breast with AUC values exceeding 0.95 in validation cohorts.^[31]^[32]

Monitoring Metabolic and Cardiovascular Disorders

Saliva testing offers a non-invasive approach to monitoring glucose dysregulation, particularly for diabetes screening and management. Salivary glucose levels have demonstrated a strong positive correlation with blood glucose, with studies reporting correlation coefficients up to r=0.85 in controlled cohorts.^[33] A salivary glucose cutoff value exceeding 1.5 mg/dL has been identified as indicative of hyperglycemia, enabling early detection of impaired glucose tolerance without invasive blood draws.^[34] This method leverages the diffusion of glucose from blood into saliva via gingival crevices and parotid ducts, providing a reliable proxy for fasting plasma glucose in resource-limited settings. In cardiovascular health, saliva-based detection of biomarkers like C-reactive protein (CRP) plays a key role in assessing inflammation and associated risks. Elevated salivary CRP levels above 3 mg/L signal heightened systemic inflammation, a predictor of cardiovascular events such as atherosclerosis and myocardial infarction.^[35] Research has validated salivary CRP as a mirror of serum levels, with significant increases observed in patients with cardiovascular disease (CVD), supporting its use in routine risk stratification.^[36] Complementing this, nitric oxide metabolites in saliva, including nitrite and nitrate, serve as indicators of endothelial function; reduced levels correlate with vascular dysfunction and hypertension, reflecting impaired nitric oxide bioavailability essential for vasodilation.^[37] Indirect evaluation of lipid profiles through saliva testing focuses on oxidative stress markers, such as malondialdehyde (MDA), a byproduct of lipid peroxidation. Elevated salivary MDA levels are associated with dyslipidemia and increased cardiovascular risk, as they indicate oxidative damage to lipoproteins in metabolic disorders like type 2 diabetes.^[38] Studies have shown significantly higher MDA in saliva of patients with altered lipid profiles, linking it to endothelial injury and plaque formation without direct lipid measurement.^[39] For metabolic syndrome, salivary alpha-amylase emerges as a stress-related biomarker tied to insulin resistance. Higher alpha-amylase activity in saliva correlates with chronic stress responses that exacerbate insulin resistance, a core feature of metabolic syndrome involving abdominal obesity, hypertension, and dysglycemia.^[40] Low copy number variations in the AMY1 gene, which encodes salivary alpha-amylase, are linked to reduced enzyme levels and heightened insulin resistance, underscoring its role in cardiometabolic vulnerability.^[41] Monitoring protocols utilizing saliva testing have advanced with point-of-care devices for daily sampling as alternatives to traditional HbA1c assessments. These devices, validated in clinical trials during the 2020s, enable real-time glucose tracking and biomarker analysis, improving adherence in diabetes management and cardiovascular risk surveillance.^[42] Such protocols facilitate frequent, home-based evaluations, reducing the need for laboratory visits while maintaining diagnostic accuracy.

Research Applications

Behavioral and Psychological Studies

Saliva testing has been instrumental in behavioral and psychological research for measuring stress responses through biomarkers such as salivary alpha-amylase (sAA) and cortisol, which reflect activation of the sympathetic-adreno-medullary (SAM) and hypothalamic-pituitary-adrenal (HPA) axes, respectively.^[43] In acute stress paradigms, such as the Trier Social Stress Test, post-task elevations in sAA have been observed in participants experiencing heightened anxiety, indicating rapid autonomic arousal.^[44] Similarly, cortisol levels rise in response to psychosocial stressors, with studies showing blunted or exaggerated responses in chronic anxiety contexts, providing insights into individual differences in stress reactivity.^[45] These biomarkers enable non-invasive assessment of both immediate and prolonged stress effects in experimental settings. In studies of cognitive function and resilience, the salivary dehydroepiandrosterone (DHEA) to cortisol ratio serves as an indicator of anabolic balance and psychological resilience under stress. Higher DHEA levels relative to cortisol have been associated with better emotional regulation and quality of life in military personnel during sustained stressors, suggesting a protective role against negative mood states.^[46] Salivary oxytocin, another key biomarker, correlates with social bonding behaviors; for instance, levels increase during interactions like gossip or vocalizations that foster affiliation, highlighting its role in modulating empathy and social recognition.^[47] These findings underscore oxytocin's involvement in prosocial cognition, with salivary measures revealing dynamic changes during bonding tasks.^[48] Behavioral correlations have been explored through salivary melatonin and testosterone, linking hormonal fluctuations to daily rhythms and aggression. In shift workers, melatonin rhythms exhibit suppression and phase delays due to disrupted sleep-wake cycles, contributing to circadian misalignment and associated behavioral impairments like reduced alertness.^[49] Testosterone levels, measured via saliva, fluctuate in aggression paradigms such as the Point Subtraction Aggression Paradigm, where post-competition rises predict reactive aggressive behavior, particularly in competitive social contexts.^[50] Research methodologies in this field often employ longitudinal sampling to capture temporal dynamics in psychological experiments. For example, repeated saliva collections over days or weeks allow tracking of biomarker trajectories in response to interventions or stressors. Twin studies from the 2010s have estimated heritability of basal cortisol levels at around 32-62%, demonstrating genetic influences on stress regulation while highlighting environmental modulation in behavioral outcomes.^[51]^[52] Applications extend to addiction research, where salivary cortisol elevations during withdrawal from substances like opiates or alcohol reflect heightened stress and symptom severity, aiding in monitoring recovery progress. Pilot studies for mental health screening have utilized salivary cortisol and sAA as non-invasive tools to identify at-risk individuals for anxiety and depression, with reviews confirming their potential as accessible biomarkers in community-based assessments.^[53]^[54]

Forensic and Toxicology Analysis

Saliva testing plays a crucial role in forensic and toxicology analysis by providing a non-invasive method to detect recent drug and alcohol use, as well as genetic material for identification purposes. Substances in saliva reflect blood concentrations through passive diffusion across oral mucosa, offering a detection window that correlates with recent exposure rather than long-term accumulation. This makes it particularly valuable for establishing probable cause in legal investigations, such as driving under the influence of drugs (DUID) cases.^[55] In drug screening, saliva testing employs immunoassays to identify common substances like tetrahydrocannabinol (THC), cocaine, and opioids, with detection windows varying by drug and usage patterns. For THC, the primary psychoactive component of cannabis, detection is possible up to 24-72 hours in occasional users, using cutoffs such as 4 ng/mL to balance sensitivity and specificity. Cocaine and its metabolites can be detected for 12-48 hours, typically up to 1-2 days following a standard dose. Opioids, including codeine and morphine, are identifiable via immunoassays with cutoffs around 30-40 ng/mL, offering a similar short detection window of hours to days that aligns with recent intake. These timelines are shorter than urine tests but advantageous for confirming impairment at the time of an incident.^[56]^[57]^[58] Alcohol detection in saliva focuses on biomarkers like ethyl glucuronide (EtG), a direct metabolite of ethanol that indicates recent consumption. EtG is detectable in saliva for up to approximately 12 hours post-ingestion (median 11.5 hours; range 3.5-11.5 hours), providing evidence of alcohol use within a narrow timeframe suitable for forensic scenarios like post-arrest testing. This biomarker outperforms direct ethanol measurement, which dissipates more rapidly, and supports investigations into alcohol-related offenses.^[59] For DNA forensics, saliva serves as a reliable source of genetic material from epithelial cells, enabling short tandem repeat (STR) profiling for identification in paternity disputes and criminal cases. A 1 mL saliva sample typically yields sufficient high-quality DNA for full STR profiles, with success rates exceeding 99% in optimized collection methods like stabilized kits. This approach has revolutionized legal identification, offering results comparable to blood samples while being less invasive.^[60] Workplace and roadside testing utilize portable oral fluid devices, such as the DrugWipe, which screen for multiple drugs through on-site immunoassays. These devices meet National Highway Traffic Safety Administration (NHTSA) validation standards for sensitivity and specificity, aiding law enforcement in DUID enforcement by detecting recent use of cannabis, cocaine, amphetamines, and opioids. Positive roadside results often prompt confirmatory lab testing, enhancing efficiency in field operations.^[61]^[55] Legal considerations in saliva testing emphasize chain-of-custody protocols to ensure evidentiary integrity, including documented collection, secure transport, and tamper-evident sealing. Admissibility in U.S. courts hinges on these procedures and scientific reliability. Courts generally accept validated saliva tests when foundational evidence demonstrates accuracy and proper handling, supporting their use in criminal prosecutions and civil matters.^[62]

Emerging Biomarkers and Innovations

Recent advancements in saliva testing have focused on novel biomarkers derived from extracellular vesicles, such as exosomes, which carry disease-specific proteins like tau for early detection of Alzheimer's disease. Pilot studies in the 2020s have demonstrated that nanoparticle tracking analysis of salivary neuronal exosomes correlates with cognitive impairment progression, enabling non-invasive monitoring of tau protein levels as a potential diagnostic indicator.^[63] Additionally, salivary microbiome profiling has emerged as a biomarker for the gut-brain axis, revealing associations between oral microbial dysbiosis and neurological conditions like Parkinson's disease through functional alterations in microbial networks.^[64] These biomarkers leverage the oral cavity's proximity to systemic pathways, offering insights into neurodegeneration without invasive procedures.^[65] Technological innovations include nanotechnology-based sensors, particularly graphene-enhanced platforms for real-time analyte detection in saliva. Graphene-based electrochemical sensors have achieved attomolar sensitivity for glucose monitoring, surpassing 1 μM thresholds and enabling continuous, non-enzymatic detection suitable for diabetes management.^[66] Complementing this, AI-driven multiplex panels integrate machine learning algorithms to analyze multiple salivary biomarkers simultaneously, improving diagnostic accuracy for systemic diseases by identifying patterns in proteomic and metabolomic data.^[67] These advances facilitate rapid, high-throughput screening with reduced false positives. Point-of-care saliva testing has evolved with smartphone-integrated devices that support multi-analyte analysis, enhancing accessibility for remote diagnostics. Post-2020 developments include microfluidic platforms coupled with smartphone apps for salivary SARS-CoV-2 detection via RNA and antibody assays, demonstrating high specificity in decentralized settings.^[69] These devices, often cleared for emergency use, pave the way for broader multi-analyte chips targeting respiratory pathogens.^[9] In research frontiers, salivary metabolomics is advancing personalized medicine by profiling small-molecule metabolites to tailor therapeutic interventions based on individual disease profiles. Untargeted metabolomic approaches in saliva have identified signatures for early disease detection, correlating with systemic metabolic shifts and enabling precision oncology and cardiology applications.^[70] Integration with wearables further supports continuous monitoring, as seen in mouthguard-type electrochemical biosensors that track salivary biomarkers like matrix metalloproteinase-8 in real-time for periodontal and systemic health assessment.^[71] Recent milestones underscore a post-2020 surge in salivary viral diagnostics, driven by multiplex PCR panels for respiratory pathogens including SARS-CoV-2, influenza, and RSV, which have improved turnaround times and clinical outcomes in outbreak scenarios.^[72] Concurrently, 2024-2025 clinical trials are validating saliva-based assays for neurodegenerative diseases, such as Raman spectroscopy of salivary extracellular vesicles for Parkinson's differential diagnosis and amyloid-beta quantification for Alzheimer's burden assessment.^[73]^[74] These efforts highlight saliva's role in bridging diagnostics and therapeutics for complex disorders.

Limitations and Criticisms

Analytical Challenges

Saliva testing encounters significant analytical challenges related to sensitivity and specificity, primarily due to the low concentrations of many biomarkers, such as hormones often below 1 ng/mL, which demand ultrasensitive detection methods. For instance, in assessing adrenal insufficiency via salivary cortisol, a cutoff of <15 nmol/L (approximately 5.4 ng/mL) yields a sensitivity of 73.9% and specificity of 69.6%, limiting its diagnostic reliability compared to serum assays.^[75] False positives are common from oral contamination, where foods, beverages, or microbial residues interfere with immunoassays, as demonstrated by studies showing altered drug detection in contaminated samples.^[76] Variability in saliva biomarker measurements arises from multiple intra-individual factors, including hydration status and smoking, which can induce fluctuations of 20-50% in analyte levels. Research on salivary proteins reports average intra-day coefficients of variation (CV) around 38%, rising to over 60% for oxidative stress markers like thiobarbituric acid reacting substances, while inter-individual and inter-day CVs reach 43-45%.^[77]^[78] Smoking exacerbates this by altering microbial composition and cytokine levels, contributing to inconsistent results across samples.^[79] Inter-laboratory discrepancies further compound these issues, often stemming from differences in assay protocols and equipment calibration.^[80] Matrix effects pose another hurdle, as saliva's high viscosity—stemming from mucins and proteins—impedes fluid flow in assays like lateral flow devices, reducing analyte dispersion and detection accuracy.^[81] Additionally, analytes such as RNA degrade rapidly in unprocessed saliva, with endogenous mRNA half-lives as short as 12.2 minutes at ambient temperature, necessitating immediate stabilization to prevent loss.^[82] Cell-free DNA fares slightly better, with half-lives around 13 hours in centrifuged samples, but enzymatic activity still accelerates breakdown.^[83] When compared to blood as the gold standard, saliva shows variable concordance; for cortisol, agreement ranges from 70-90%, with 90% peak concordance in morning samples but lower reliability for pulsatile patterns.^[84] Peptide hormones exhibit even poorer correlation, often below 70%, due to limited diffusion across salivary glands and greater susceptibility to matrix interference.^[80] Mitigation strategies include normalization techniques, such as adjusting biomarker levels to salivary creatinine or total protein content to account for dilution effects from hydration variability, improving quantitative accuracy in renal and metabolic assessments.^[85] Quality controls like centrifugation and filtration reduce matrix effects by lowering viscosity and removing debris, enhancing assay performance; for example, nylon wool filtration achieves an 80% viscosity reduction with minimal protein loss.^[86] Advanced preprocessing, including microfluidic extraction, further minimizes degradation and contamination risks.^[87]

Standardization and Validation Issues

One major barrier to the widespread adoption of saliva testing is the lack of uniform protocols for sample collection, processing, and analysis, which results in inconsistent reference ranges across studies. For instance, salivary cortisol norms vary significantly by age, ethnicity, and socioeconomic status, with racial/ethnic differences in diurnal rhythms—such as flatter morning-to-evening slopes among African Americans—complicating the establishment of universal benchmarks.^[88]^[89]^[90] These variations arise from differences in collection methods, such as passive drool versus swabs, and highlight the need for harmonized pre-analytical procedures to ensure comparability.^[91]^[92] Validation gaps further hinder reliability, as many studies from the 2010s involved small sample sizes, often fewer than 1,000 participants, which limits statistical power and generalizability for clinical applications.^[93] Regulatory frameworks, including the FDA's 2018 Bioanalytical Method Validation Guidance and EMA's 2011 guideline (with ongoing updates discussed in 2022 bioanalysis white papers), apply to salivary assays but emphasize the need for comprehensive validation of sensitivity, specificity, and reproducibility in diverse populations.^[94]^[95]^[96] As of 2025, no salivary diagnostic tests have received FDA approval for evaluating risks of dental caries, periodontal disease, or head and neck cancers. The FDA's April 2024 final rule phases in increased oversight of laboratory-developed tests (LDTs) by 2028 to ensure safety and efficacy. The American Dental Association issued a guide to salivary diagnostics in January 2025.^[97]^[98]^[99] Without large-scale, multicenter trials exceeding 10,000 participants, these assays struggle to meet evidentiary standards for routine diagnostic use.^[100] Ethical concerns, particularly around privacy in genetic testing, pose additional procedural barriers, as saliva samples from direct-to-consumer kits can reveal sensitive hereditary information without robust data protection measures.^[101]^[102] Equity issues exacerbate these challenges in low-resource settings, where limited access to validated laboratory infrastructure and trained personnel restricts the scalability of non-invasive saliva testing despite its potential cost benefits.^[103]^[104] Disparities between commercial and research applications amplify validation issues, with many over-the-counter saliva kits—such as early COVID-19 tests—lacking peer-reviewed evidence, as evidenced by only 35% of 185 commercial assays passing independent laboratory evaluations for accuracy and reliability.^[105]^[93] In contrast, research protocols often incorporate rigorous controls, but commercial products prioritize accessibility over standardization, leading to overhyped claims without sufficient clinical corroboration.^[92] Looking ahead, international consortia are addressing these barriers through harmonization efforts, such as the 2024 guidelines on pre-analytical variables for salivary biomarkers, which recommend standardized collection and storage protocols to improve reproducibility across global studies.^[100] Initiatives from organizations like the Society for Salivary Bioscience and commercial leaders such as Salimetrics further promote validated collection aids and quality controls to bridge regulatory and procedural gaps.^[91]^[106] These developments aim to foster equitable, evidence-based integration of saliva testing into clinical practice.

References

[1]
Evaluation of Salivary Diagnostics: Applications, Benefits, Challenges, and Future Prospects in Dental and Systemic Disease Detection - PMC
Summary of each segment:
[2]
A Review on Saliva-Based Health Diagnostics: Biomarker Selection ...
Jun 6, 2023 · This review paper talks about the relevance of saliva and its usefulness as a biosensor. Also, it has recommendations that need to be considered to enable it ...
[3]
Saliva as a Diagnostic Tool for Systemic Diseases—A Narrative ...
Saliva has emerged as a powerful diagnostic tool due to its non-invasive collection, straightforward storage, and ability to mirror systemic health.4. Role Of Saliva · 4.4. Saliva Proteome... · 5. Saliva As A Diagnostic...
[4]
(PDF) The History of Salivary Diagnostics - ResearchGate
Jun 30, 2015 · The history of using saliva as an indicator of what is taking place within the human body dates back centuries. It is said that in ancient ...
[5]
Clinical and diagnostic utility of saliva as a non-invasive ... - NIH
This systematic review presents the latest trends in salivary research and its applications in health and disease. Among the large number of analytes present in ...<|control11|><|separator|>
[6]
Methods of collection of saliva - A Review - Int J Oral Health Dent
Successful measurement of salivary parameters requires optimal collection procedures, which is one of the most important pre analytical steps. The present paper ...
[7]
Saliva-based microfluidic point-of-care diagnostic - PMC
Our review article will address this gap in knowledge by exploring the potential of saliva as a diagnostic body fluid, the complexities of using saliva on ...Transport Of Biomolecules... · Commercially Available... · Table 1
[8]
A Review of Selected Studies That Determine the Physical and ...
Saliva contains 99.5% water, 0.3% protein, and 0.2% inorganic and organic substances [7]. The most common inorganic constituents are sodium, potassium, calcium, ...
[9]
[PDF] Saliva composition and functions: A comprehensive review
Mar 1, 2008 · Saliva is mostly water with electrolytes, proteins, and antimicrobial factors. It helps with taste, buffers acids, and lubricates/protects oral ...
[10]
Secretory immunity with special reference to the oral cavity - NIH
The two principal antibody classes present in saliva are secretory IgA (SIgA) and IgG; the former is produced as dimeric IgA by local plasma cells (PCs) in the ...
[11]
Measurement of Salivary Cortisol Concentration in the Assessment ...
Studies over the past 15 to 20 yr have demonstrated that cortisol in the saliva is in equilibrium with, and correlate with the free (unbound) fraction of the ...
[12]
Salivary Cortisol Can Replace Free Serum Cortisol Measurements ...
Salivary cortisol level can be used as a surrogate of free serum cortisol level in patients with septic shock with very good correlation.
[13]
Effect of various types of milk on salivary pH among children - Nature
Sep 13, 2023 · The flow rate of unstimulated saliva is about 0.3–0.4 ml/min [15], and the normal pH range of saliva is 6.2–7.6 [16]. The salivary flow and ...
[14]
Circadian rhythms in human salivary flow rate and composition - NIH
Unstimulated whole saliva showed significant circadian rhythms in flow rate and in the concentrations of sodium and chloride but not in protein, potassium, ...
[15]
Salivary biomarkers in oral squamous cell carcinoma - PMC - NIH
Salivary biomarkers are a very promising noninvasive approach to oral cancer detection. In monitoring the disease progression and patient's response to ...
[16]
Estimation of salivary and serum CYFRA 21-1 levels in patients with ...
Mar 21, 2023 · The present study is aimed to estimate salivary and serum levels of CYFRA 21-1 in oral squamous cell carcinoma (OSCC) patients and to compare them with healthy ...
[17]
Concomitant Analysis of Salivary Tumor Markers—A New ...
Jul 3, 2006 · Results: Significant increases (of 400%) in salivary concentrations of Cyfra 21-1, tissue polypeptide antigen, and CA125 were shown. Salivary ...
[18]
Biomarkers of pancreatic cancer - PubMed
Apr 5, 2011 · ... saliva samples, are now applied for the diagnosis of pancreatic cancer. ... CA-19-9 Antigen / analysis; Calcium-Binding Proteins / analysis ...
[19]
Increased telomerase activity and hTERT expression in human ...
Of the 24 malignant tumors, 15 revealed strong telomerase activity. The non-neoplastic salivary glands appeared to have a negative telomerase expression.
[20]
Telomerase activity in the differential diagnosis of pancreatic mass
The detection of telomerase activity in pancreatic mass tissue provides early evidence of a cancerous process that requires a well-timed surgical treatment.Missing: salivary | Show results with:salivary
[21]
Salivary biomarkers in breast cancer diagnosis: A systematic review ...
Mar 22, 2022 · Our meta‐analysis showed that saliva might be a promising, efficient, and noninvasive biomarker with the potential to differentiate between patients with and ...
[22]
The Promising Role of miR-21 as a Cancer Biomarker and Its ... - NIH
Even at low levels, miRNA profiles could establish a better diagnosis by classifying tumors into 11 categories (including colon, ovary, lung, breast, ...Missing: proteomic | Show results with:proteomic
[23]
Human salivary microRNAs in Cancer - PMC - PubMed Central - NIH
Salivary miRNAs have emerged as specific group of biomolecules with high value as diagnostic salivary biomarkers of cancer.
[24]
https://pubmed.ncbi.nlm.nih.gov/21464582/
[25]
Nanophotonic sensors and AI for a new possible approach for ...
This paper aims to outline a feasibility analysis of a novel approach utilizing advanced nanophotonic sensors and AI to address these diagnostic issues.
[26]
Artificial intelligence in cancer: applications, challenges, and future ...
31 Oct 2025 · The integration of AI in cancer research and clinical practice encompasses advancing screening and diagnostic accuracy, improving precision ...
[27]
Validation of salivary glucose as a screening tool of diabetes mellitus
Sep 22, 2022 · Aim: To measure fasting plasma glucose (FPG) and compare and correlate with salivary glucose levels in normal and diabetic individuals. Also, ...
[28]
Accuracy of Salivary Glucose Assessment in Diagnosis of Diabetes ...
Salivary glucose was significantly correlated to FBS with strong positive association (r = 0.67, P value < 0.001 in control group, r = 0.56, P value < 0.001in ...
[29]
Salivary biomarkers and cardiovascular disease: a systematic review
Aug 28, 2018 · Statistically significant increases of salivary CRP were present with CVD in every study that analyzed it. The remaining six markers ...
[30]
Assessing salivary C-reactive protein: longitudinal associations with ...
Assessing salivary C-reactive protein: longitudinal associations with systemic inflammation and cardiovascular disease risk in women exposed to intimate partner ...
[31]
Nitrate-responsive oral microbiome modulates nitric oxide ... - PubMed
Aug 20, 2018 · NO (generated from both NO2- and L-arginine) regulates vascular endothelial function and therefore blood pressure (BP).
[32]
Oxidative stress, antioxidant status and lipid profile in the saliva of ...
Salivary MDA levels, a product of lipid peroxidation, were significantly increased among diabetics together with uric acid. However, GSH levels were similar to ...
[33]
Correlation of Plasma Lipid Profile with Salivary Oxidative Stress ...
Jun 20, 2014 · Results: The association of plasma LDL with salivary MDA was found to be positive and significant and that with salivary thiols was negative and ...
[34]
Salivary α-amylase activity is associated with cardiometabolic and ...
Mar 18, 2024 · Salivary α-amylase activity (sAAa) inversely correlates with obesity and insulin resistance in adults and children. However, the connection ...Missing: syndrome | Show results with:syndrome
[35]
Association between salivary amylase (AMY1) gene copy numbers ...
Low AMY1 CNVs correlated with high insulin resistance in asymptomatic Korean men, and such a relationship presented differently according to the status of ...
[36]
Salivary glucose as a non-invasive biomarker of type 2 diabetes ...
Sep 1, 2018 · Conclusions: Salivary glucose is comparable to blood glucose in diagnosing and monitoring T2DM and is considered more advantageous than blood ...
[37]
Salivary mental stress proteins - PubMed
Oct 21, 2013 · In this review, we summarize the critical knowledge of the positive and negative attributes and data gaps pertaining to each salivary stress ...
[38]
Direct and moderating links of salivary alpha-amylase and cortisol ...
sAA was positively related to anxiety, while sAA reactivity moderated associations between cortisol reactivity and problem behavior. Results highlight the ...
[39]
Salivary cortisol and α-amylase: subclinical indicators of stress as ...
Results supported the use of salivary cortisol and α-amylase as potential diagnostic tools for detecting stress-induced cardiac diseases.
[40]
Steroid Hormones as Modulators of Emotional Regulation in Male ...
Results: We found that the quality of life was positively related to DHEA, but not cortisol levels. Negative mood increases were related to lower levels of DHEA ...
[41]
Gossip increases oxytocin levels in a near real-life situation - PubMed
Salivary oxytocin and cortisol levels were measured. Oxytocin increased significantly in the gossip compared to the emotional non-gossip conversation. A ...
[42]
Social vocalizations can release oxytocin in humans - PubMed - NIH
Sep 7, 2010 · Our results suggest that vocalizations may be as important as touch to the neuroendocrine regulation of social bonding in our species.
[43]
Changes in the diurnal rhythms of cortisol, melatonin, and ... - PubMed
Melatonin amplitude was suppressed, cortisol phase was delayed, and testosterone rhythm was unaffected by increasing night shifts.
[44]
Testosterone responses to competition predict future aggressive ...
After the competition, participants performed the Point Subtraction Aggression Paradigm (PSAP), a behavioural measure of reactive aggression ... These findings ...Missing: behavioral | Show results with:behavioral
[45]
Heritability of cortisol regulation in children - PubMed
Method: The aim of this study was to estimate genetic and environmental influences on basal cortisol levels in a sample of 151 twin pairs aged 9-16 years.
[46]
Heritability of cortisol levels: review and simultaneous ... - PubMed
Results of a simultaneous analysis of 5 comparable twin studies suggest a heritability of 62%. Hence, we conclude that, to understand the contribution of ...
[47]
Salivary cortisol during opiate dependence and withdrawal - PubMed
There was an 80% reduction in withdrawal symptom severity between the first 12 days and the subsequent 12 days of treatment. Salivary cortisol fell from a mean ...
[48]
Salivary Biomarkers of Stress, Anxiety and Depression - PubMed
Feb 1, 2021 · The following are promising salivary biomarkers of stress, anxiety or depression: cortisol, immunoglobulin A (sIgA), lysozyme, melatonin, α-amylase (sAA), ...Missing: mental screening
[49]
Drug Testing in Oral Fluid - PMC - NIH
Oral fluid concentrations of basic drugs such as the amphetamines, cocaine and some opioids are similar or higher than those in plasma. Tetrahydrocannabinol ( ...
[50]
THC Saliva Test: Detection Time and Accuracy Explained
Rating 5.0 (4) THC can be detected in saliva for 24-72 hours for occasional users, and 1-7 days for regular users. Saliva tests are reliable for recent use.
[51]
Pharmacokinetics of Cocaine and Metabolites in Human Oral Fluid ...
In general, use of a typical 100 mg dose of cocaine could be detected in oral fluid for either cocaine or BE for approximately 1–2 days.
[52]
Selection of an immunoassay screening cutoff concentration for ...
Previously proposed regulations from the Substance Abuse and Mental Health Services Administration (SAMHSA) have recommended 40 μg/L as a cutoff concentration.
[53]
Ethyl glucuronide concentrations in oral fluid, blood, and urine after ...
The detection time for EtG was median 11.5 h (range 3.5-11.5 h) in oral fluid. According to this, the detection time for EtG in oral fluid is therefore only a ...
[54]
8 facts most people don't know about DNA from saliva
Feb 1, 2019 · Multiple studies confirm DNA extracted from Oragene/saliva samples result in DNA of the highest integrity, performing equivalently to blood for ...Missing: paternity success rate
[55]
[PDF] Marijuana-Impaired Driving – A Report to Congress - NHTSA
Devices that collect oral fluid for laboratory testing appear to be a reliable means of testing for recent drug use. The technology to rapidly, accurately and.
[56]
[PDF] Use of Oral Fluid to Detect Drugged Drivers: A Toolkit - Soft-Tox.org
An evaluation of on-site oral fluid drug testing devices DrugWipe 5+ and Rapid STAT using oral fluid for confirmation analysis. Journal of Analytical ...
[57]
Employing nanoparticle tracking analysis of salivary neuronal ...
Feb 7, 2023 · A novel approach to correlate the salivary exosomes and their protein cargo in the progression of cognitive impairment into Alzheimer's disease.Missing: 2020s | Show results with:2020s
[58]
Microbiome signatures of virulence in the oral-gut-brain axis ...
Oct 15, 2024 · Our study reveals a significant connection between the oral and gut microbiomes in PD patients, emphasizing the functional role of this oral-gut ...Results · Oral Microbiome In The Gut... · Discussion
[59]
Oral microbiome brain axis and cognitive performance in older adults
Apr 7, 2025 · These results suggest that Rothia (salivary and lingual) has the strongest correlation with blood biomarkers of AD, and the oral microbiota is ...
[60]
Graphene-Based Glucose Sensors with an Attomolar Limit of ...
Apr 3, 2025 · The biosensor achieves an attomolar limit of detection and a sensitivity of 10.6 mV/decade, outperforming previously reported glucose sensors.
[61]
Artificial intelligence in salivary biomarker discovery and validation ...
Jun 19, 2023 · This review summarized the role and current application of techniques based on artificial intelligence for salivary biomarker discovery and validation
[62]
Integrating Artificial Intelligence with Salivary Biomarkers for ...
Aug 28, 2025 · Objective: To develop and validate an AI-driven diagnostic system using salivary biomarkers for early detection of diabetes mellitus, ...
[63]
Smartphone-based corona virus detection using saliva: A mini-review
Mar 8, 2023 · In this review, recent advances in precise salivary-based SARS-CoV-2 diagnosis using smartphones via viral RNA detection, antibody identification, and viral ...Missing: approvals | Show results with:approvals
[64]
Saliva metabolomics: a non-invasive frontier for diagnosing and ...
May 24, 2025 · Salivary metabolomics represents a powerful noninvasive approach for diagnosing, monitoring, and managing oral diseases.
[65]
A Wearable Electrochemical Biosensor for Salivary Detection of ...
Jul 26, 2025 · A wearable electrochemical biosensor integrated into a smart mouthguard enables the non-invasive detection of salivary MMP-8 for early ...
[66]
Performance Assessment of a Multiplex Real-Time PCR Assay ... - NIH
Oct 22, 2024 · The goal of this study was to compare the performance of three multiplex real-time PCR-based platforms for the detection of SARS-CoV-2, Flu A, Flu B, and RSV.
[67]
Saliva and Extracellular Vesicles for Parkinson's Disease
The objective of this project is the validation of Raman analysis of saliva and salivary extracellular vesicles (EV) for the differential diagnosis of ...
[68]
Salivary levels of amyloid beta reflect brain amyloid beta burden in ...
Jun 9, 2025 · Saliva as a biofluid has been explored for many neurological disorders, including AD [6]. Notably, many past studies have quantified levels of ...
[69]
The Reliability of Salivary Cortisol Compared to Serum Cortisol for ...
Sep 19, 2023 · For a cut-off of salivary cortisol < 15 nmol/L, sensitivity was 73.9% and specificity 69.6%. Our data do not support salivary cortisol as a ...3. Results · 3.1. High-Dose Acth... · 3.2. Low-Dose Acth...
[70]
Effects of Oral Fluid Contamination on Two Oral Fluid Testing Systems
Mar 6, 2013 · This study describes the effects of 19 different foods, beverages and vinegars on two test systems, the Concateno Certus and Orasure Intercept.
[71]
Variability Assessment of 90 Salivary Proteins in Intra-Day and Inter ...
For the 90 proteins detectable in > 50% of samples, the average CVs for intra-day, inter-day, intra-individual, and inter-individual samples were 38%, 43%, 45%, ...
[72]
Variability of thiobarbituric acid reacting substances in saliva - PubMed
Intraindividual variability was very high in both genders with coefficients of variation of more than 60%. Interindividual variability was higher in men than in ...
[73]
Cigarette Smoking Modulation of Saliva Microbial Composition ... - NIH
Nov 7, 2018 · In the present study, we investigated the effects of cigarette smoking on bacterial diversity and host responses compared to healthy nonsmoking controls.
[74]
Salivary biomarkers detection: Analytical and immunological ...
This review focuses on the recent advances and main challenges employed in the detection and quantification of salivary biomarkers by separation, immunological ...
[75]
Development of Paper-Based Analytical Devices for Minimizing the ...
Jun 13, 2018 · As expected, the increasing salivary viscosity retards the fluid dispersion. However, an unexpected result of changing the viscosity was the ...
[76]
Characterization of RNA in saliva - PubMed - NIH
Endogenous salivary beta-actin mRNA degraded more slowly than exogenous beta-actin mRNA, with half-lives of 12.2 and 0.4 min, respectively (P <0.001). Salivary ...
[77]
Evaluating Pre-Analytical Variables for Saliva Cell-Free DNA Liquid ...
May 9, 2023 · (a), Saliva supernatant cfDNA half-life = 13.18 h. Pooled saliva samples were centrifuged immediately at 2600× g for 15 min at 4 °C. Cell-free ...
[78]
The use of saliva for assessment of cortisol pulsatile secretion by ...
The percentage concordance increased to 90% when concording only the morning cortisol peaks in plasma and saliva up to 11:00 h. The deconvolution of the most ...Missing: 70-90% | Show results with:70-90%
[79]
Salivary Creatinine Estimation as an Alternative to Serum ... - NIH
Saliva can be used as a noninvasive alternative to serum for creatinine estimation. 1. Introduction. Chronic kidney disease (CKD) is progressive reduction in ...
[80]
Filtered Saliva for Rapid and Accurate Analyte Detection for POC ...
May 24, 2024 · The results show that a 20 mg nylon wool (NW) filter shows an 80% change in viscosity reduction with only a 6% reduction in protein content, ...
[81]
Salivary diagnostics: opportunities and challenges - PubMed
Oct 21, 2024 · This review highlights the biomarkers in saliva and their role in identifying relevant diseases. It provides an overview and discussion ...
[82]
Revisiting the cortisol reference ranges in humans: the role of demographics - Endocrine
### Key Findings on Cortisol Reference Ranges by Demographics
[83]
Racial and Ethnic Differences in Diurnal Cortisol Rhythms in ...
The analyses revealed racial/ethnic differences in diurnal cortisol rhythms, with African Americans having significantly flatter morning-to-evening cortisol ...
[84]
Socioeconomic and race/ethnic differences in daily salivary cortisol ...
The objective of this study was to determine if daily cortisol patterns, a biomarker of the stress response, differ by race/ethnicity and socioeconomic status.
[85]
Rigor and Reproducibility (Part 2): How Good Are Your ... - Salimetrics
Rigor and Reproducibility is a three-part series on the steps researchers can take to improve the quality of their salivary bioscience data.
[86]
Salivary diagnostics: opportunities and challenges - PMC - NIH
This review highlights the biomarkers in saliva and their role in identifying relevant diseases. It provides an overview and discussion about the current ...
[87]
Evaluation of Salivary Diagnostics: Applications, Benefits ...
Jan 16, 2025 · The advantages of saliva as a diagnostic medium lie in its non-invasive collection process, which is simple, painless, and cost-effective ...
[88]
[PDF] Bioanalytical Method Validation - Guidance for Industry | FDA
May 24, 2018 · The recommendations in this guidance only pertain to the validation of assays to measure in vivo biomarker concentrations in biological ...
[89]
[PDF] Guideline Bioanalytical method validation
Jul 21, 2011 · This guideline provides recommendations for the validation of bioanalytical methods applied to measure drug concentrations in biological ...
[90]
2022 White Paper on Recent Issues in Bioanalysis: Fda Draft ...
This 2022 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop and is aimed to provide the bioanalytical ...
[91]
Guidelines for the standardization of pre‐analytical variables for ...
Dec 30, 2024 · Factors such as circadian rhythms, individual variations, and the influence of medications must be carefully considered to ensure the ...<|separator|>
[92]
Ethical Issues Associated With Direct-to-Consumer Genetic Testing
Jun 3, 2023 · This review aims to provide an overview of the services these companies purport to provide as well as highlight important ethical issues of the service.
[93]
Shedding Privacy Along with our Genetic Material: What Constitutes ...
Law doesn't always adequately address unauthorized uses of individuals' DNA. Ethics can help establish legal privacy protections that work.
[94]
Saliva-based methods for SARS-CoV-2 testing in low - NIH
Saliva testing can lessen two major challenges faced by lower- and middle-income countries: constrained resources and overburdened health workers. Saliva ...
[95]
Saliva in the Spotlight | myadlm.org
Jan 1, 2022 · Punyadeera sees saliva diagnostics as potentially having a transformative effect on medical care by “increasing access in low resource settings ...
[96]
Salivary Biomarkers Identification: Advances in Standard and ... - MDPI
By integrating multi-biomarker panels, clinicians can achieve higher accuracy in disease detection and progression monitoring, paving the way for personalized ...