Fact-checked by Grok 2 weeks ago

EC50

EC50, also known as the half-maximal effective concentration, is a quantitative measure in pharmacology and toxicology that represents the concentration of a drug, agonist, or other substance required to induce a response that is 50% of the maximum possible effect in a biological system, such as a cell culture or assay.^[1] This parameter is derived from dose-response experiments, where it marks the midpoint of a sigmoidal curve plotting response against logarithmic concentration, enabling precise assessment of potency.^[2] Unlike the inhibitory concentration (IC50), which applies to antagonists reducing activity to 50% of baseline, EC50 specifically evaluates stimulatory effects from agonists or activators.^[1] In drug development and pharmacological research, EC50 serves as a critical benchmark for comparing the relative potencies of compounds, guiding decisions on dosing and efficacy.^[3] For instance, lower EC50 values indicate higher potency. It is commonly calculated using nonlinear regression models, such as the log-logistic function, fitted to experimental data from in vitro assays, and is essential for distinguishing full agonists (which reach 100% efficacy) from partial agonists (with submaximal efficacy).^[2] Beyond pharmacology, EC50 finds applications in environmental toxicology to evaluate substance toxicity, such as the 12.5 mg/L value for chlorobenzene inhibiting algal growth by 50%.^[3] The determination of EC50 requires careful experimental design, including normalization of responses to define baseline (0%) and maximum (100%) plateaus, often using controls like vehicle-treated samples.^[1] Variations in EC50 can arise from factors like exposure time, receptor density, or assay conditions, underscoring the need for standardized protocols in comparative studies.^[4] Overall, EC50 remains a foundational metric for advancing therapeutic candidates and understanding molecular interactions in biological pathways.^[5]

Definition and Fundamentals

Definition

The EC50, or half-maximal effective concentration, is defined as the concentration of an agonist or drug that induces 50% of the maximum possible response in a biological system.^[5] This parameter quantifies the potency of a substance by identifying the point on a dose-response curve where half the maximal effect is achieved.^[4] EC50 values are typically expressed in units of concentration, such as molarity (e.g., nanomolar [nM] or micromolar [μM]), reflecting the amount of substance required to elicit the response in experimental or physiological contexts.^[6] In sigmoidal dose-response curves, which plot response magnitude against logarithmic concentration, the EC50 corresponds to the inflection point, providing a standardized metric for comparing drug effects across systems.^[7] It plays a central role in assessing drug potency, where lower EC50 values indicate greater potency.^[1]

Pharmacological Significance

The EC50 value serves as a key measure of an agonist's potency, representing the concentration required to produce 50% of the maximum possible response in a biological system, thereby quantifying how effectively the agonist activates a receptor or pathway.^[8] Unlike antagonists, which are evaluated using IC50 values to assess their inhibitory potency by measuring the concentration needed to block 50% of a response, EC50 specifically applies to stimulatory effects and helps differentiate agonists based on their ability to elicit responses without implying blockade.^[9] This distinction is crucial in pharmacological studies, as it allows researchers to profile compounds as activators or inhibitors early in development.^[10] In drug discovery, EC50 is integral to high-throughput screening (HTS), where it enables rapid evaluation of thousands of compounds for their potency in cellular or biochemical assays, identifying hits with desirable activation profiles.^[11] During lead optimization, EC50 data guide iterative modifications to enhance potency, such as reducing the value to improve a candidate's efficacy while minimizing off-target effects, and facilitate comparisons across diverse assays to select the most promising molecules for advancement.^[12] For instance, in G protein-coupled receptor studies, EC50 comparisons help rank agonists by their relative strengths, streamlining the selection of leads for further preclinical testing.^[9] EC50 influences the therapeutic index by providing a potency benchmark that, when contrasted with toxicity measures like LD50 (half-maximal lethal dose), helps estimate the safety margin of a drug, where a lower EC50 relative to the corresponding ED50 indicates a wider index and reduced risk of adverse effects at therapeutic doses.^[13] In clinical pharmacology, this informs dosing strategies, as compounds with lower EC50 values require smaller doses to achieve effective concentrations, optimizing patient compliance and minimizing side effects in regimens for conditions like hypertension or cancer.^[14] Such assessments ensure that dosing aligns with potency to maintain efficacy within the therapeutic window.^[15]

Measurement and Calculation

Experimental Determination

The experimental determination of EC50 relies on dose-response experiments conducted in various assay formats to quantify the concentration of a compound that elicits half-maximal biological response. Common assay types include in vitro cell-based assays, receptor binding studies, and in vivo animal models, each tailored to capture functional potency under controlled conditions.^[16]^[17] In vitro cell-based assays, such as those using adherent cell lines in multi-well plates, measure functional responses like receptor activation or cell proliferation. For example, in GPCR pharmacology, cells expressing target receptors are seeded at densities of 10,000–50,000 per well, incubated with compounds, and responses assessed via fluorescence-based readouts, such as calcium mobilization using dyes like Fluo-4, where increased fluorescence indicates activation. Receptor binding studies, often employing radiolabeled ligands, evaluate competitive displacement in membrane preparations or whole cells to infer potency, with bound radioactivity quantified by scintillation counting after filtration or centrifugation. In vivo animal models, such as rat capsaicin-induced eye wipe assays for pain modulation, involve administering compounds via oral or intravenous routes to groups of rodents and observing behavioral endpoints like reduced wiping frequency.^[18]^[19]^[17] Dose-response experiments follow standardized protocols to generate raw data curves. Serial dilutions of the test compound are prepared in a vehicle like DMSO (typically <1% final concentration) across a 5–6 log10 range, such as from 10 nM to 100 μM, to bracket the expected EC50. These are applied to the assay system—cells, membranes, or animals—and responses measured after equilibrium incubation (e.g., 30–60 minutes for in vitro, hours for in vivo). Data collection involves replicating measurements, often in triplicate wells for in vitro assays, to produce percentage response relative to maximal (100%) and minimal (0%) controls, yielding sigmoid-shaped curves when plotted against log concentration. These raw curves provide the empirical data for subsequent EC50 calculation.^[16]^[20]^[17] Accuracy in EC50 determination is influenced by several experimental factors. Assay variability, including pipetting errors or inconsistent incubation times, can be minimized through automation and standardized protocols. Tissue or cell preparation quality, such as viability >90% in cell-based assays or uniform membrane homogenization in binding studies, directly impacts reproducibility. Statistical replicates, typically n=3–6 per concentration across multiple independent runs, enhance reliability by allowing assessment of intra- and inter-assay coefficients of variation, ideally <20%.^[20]^[16]^[17]

Mathematical Derivation

The mathematical derivation of EC50 begins with the modeling of the dose-response relationship using a sigmoidal logistic function, known as the Hill-Langmuir equation, which describes the effect E as a function of agonist concentration [A]:

E = E_{\max} \frac{[A]^n}{EC_{50}^n + [A]^n}

Here, E_{\max} represents the maximum response, EC_{50} is the concentration producing half-maximal effect, and n is the Hill coefficient reflecting the slope or cooperativity of the curve.^[21] This equation is derived from the law of mass action applied to receptor binding equilibria, assuming a hyperbolic relationship scaled for multiple binding sites or cooperative effects. To estimate EC_{50} from experimental data, non-linear regression is applied to fit the observed responses to the logistic model, minimizing the sum of squared residuals via least-squares optimization. Algorithms such as the Levenberg-Marquardt method iteratively adjust parameters (E_{\max}, EC_{50}, n, and baseline if needed) to achieve convergence, with confidence intervals derived from the asymptotic covariance matrix or bootstrapping for robust uncertainty quantification. Software like GraphPad Prism implements these fits, constraining EC_{50} > 0 and typically requiring data points spanning at least two concentrations below and above the inflection to ensure parameter identifiability.^[21] Dose-response data are commonly log-transformed by plotting response against \log_{10}([A]) on the x-axis, transforming the equation into:

E = E_{\max} \frac{1}{1 + 10^{n(\log_{10} EC_{50} - \log_{10} [A])}}

This linearizes the concentration scale, which spans several orders of magnitude, and assumes constant relative errors in concentration measurements, thereby minimizing heteroscedasticity and improving fit stability for pEC_{50} = -\log_{10} EC_{50} estimation.

Theoretical Relationships

Relation to Affinity

In pharmacology, affinity refers to the strength of binding between a ligand and its receptor, quantitatively defined as the inverse of the dissociation constant K_d, where K_d is determined through equilibrium binding assays using radiolabeled ligands.^[22] The K_d represents the ligand concentration at which half of the receptors are occupied at equilibrium, providing a direct measure of binding strength independent of downstream cellular responses.^[22] The EC50, as a functional measure of potency, relates to affinity but is influenced by both binding and signal transduction efficiency. For full agonists in systems lacking receptor reserve (spare receptors), the EC50 closely approximates the K_d, reflecting that half-maximal response requires near half-maximal occupancy.^[23] However, in the operational model of agonism, this relationship is modulated by efficacy, expressed as:

\text{EC}_{50} \approx \frac{K_d}{1 + \frac{[R_t]}{K_E}}

where [R_t] is the total receptor concentration and K_E is the transducer efficacy constant; when receptor reserve is present (high [R_t]/K_E), the denominator increases, shifting EC50 leftward such that EC50 < K_d.^[23]^[22] In contrast, for partial agonists with inherently lower efficacy (smaller \tau = [R_t]/K_E), the EC50 more closely mirrors the K_d even in systems with receptor reserve, as maximal response requires greater occupancy and amplification is limited.^[24] This distinction highlights how EC50 provides insight into affinity tempered by agonism type, with full agonists showing greater divergence from K_d under conditions of high reserve.^[22]

Relation to Efficacy

Efficacy in pharmacology refers to the capacity of a ligand-bound receptor to elicit a cellular response beyond mere binding, distinguishing it from affinity by focusing on the downstream activation of signaling pathways.^[25] This property is quantitatively assessed through the maximum achievable effect, denoted as E_max, which represents the upper limit of the drug's response in a given system regardless of dose.^[26] For full agonists, E_max approaches the system's full response capacity, whereas partial agonists produce a submaximal E_max even at saturating concentrations due to inherently lower activation efficiency.^[27] The relationship between efficacy and EC₅₀ is illuminated by the operational model of agonism, which integrates receptor binding with stimulus-response transduction. In this framework, efficacy is parameterized by τ, defined as:

\tau = \frac{[R_t]}{K_e}

where [R_t] is the total receptor concentration and K_e is the efficacy constant representing the concentration of receptor complexes needed to produce 50% of E_max.^[23] Higher τ values indicate greater operational efficacy, driven by abundant receptor density or efficient coupling to effectors, which amplifies the response and influences the position of the dose-response curve, including the EC₅₀. This model demonstrates that EC₅₀ depends on both affinity (K_A) and efficacy (τ), allowing agonists with varying efficacy to exhibit distinct response profiles.^[23] Partial agonists exemplify the decoupling of potency from efficacy: despite producing a lower E_max due to reduced τ, their EC₅₀—the concentration yielding 50% of their own maximal response—can approximate that of full agonists when affinities are similar, particularly in systems with limited receptor reserve.^[23] This independence highlights how EC₅₀ primarily reflects the concentration needed for half-activation of the agonist's intrinsic capability, rather than the absolute response magnitude, enabling therapeutic selectivity in drug design.^[28]

Integration with the Hill Equation

The Hill equation extends the basic logistic model for dose-response relationships by incorporating a coefficient that accounts for cooperative interactions in ligand binding, allowing for a more accurate description of sigmoidal curves in systems exhibiting allosteric effects.^[29] In pharmacology, this integration is particularly valuable for analyzing receptor-ligand interactions where binding at one site influences affinity at others, as seen in multi-subunit proteins like ion channels or G-protein-coupled receptors.^[30] The full Hill equation for the effect E as a function of agonist concentration [A] is given by:

E = E_{\max} \cdot \frac{[A]^n}{EC_{50}^n + [A]^n}

where E_{\max} is the maximum effect, EC_{50} is the concentration producing half-maximal effect, and n is the Hill coefficient.^[29] This form modifies the standard EC50 model by raising both the concentration terms to the power n, which adjusts the steepness of the curve.^[30] The equation derives from the Langmuir adsorption isotherm adapted for cooperative binding in multi-subunit systems, assuming a simplified all-or-nothing mechanism where n ligands bind simultaneously to a receptor with n sites: nL + R \rightleftharpoons L_nR, leading to fractional occupancy \frac{[L]^n}{K_A^n + [L]^n}, where K_A relates to EC_{50}.^[29] This derivation, originally proposed by Hill in 1910 for hemoglobin-oxygen binding, provides an empirical approximation for complex cooperative kinetics without requiring detailed allosteric models. In curve fitting, n is estimated alongside EC_{50} using nonlinear regression on experimental dose-response data, often via four-parameter logistic models, to quantify deviations from hyperbolic binding.^[30] The Hill coefficient n interprets cooperativity: n = 1 indicates non-cooperative, independent binding sites, akin to the simple Michaelis-Menten or Langmuir case; n > 1 signifies positive cooperativity, where initial binding enhances subsequent binding (e.g., in hemoglobin, yielding steeper curves and lower apparent EC_{50}); and n < 1 denotes negative cooperativity, where binding reduces affinity at remaining sites (e.g., in some enzyme inhibitions, resulting in shallower curves).^[29] Deviations from n = 1 thus signal allosteric effects or multiple interacting binding sites, aiding in mechanistic insights beyond basic potency measures.^[30]

Limitations and Applications

Key Limitations

The determination of EC50 assumes steady-state conditions where ligand-receptor interactions reach equilibrium, allowing for a reliable measure of potency. However, this assumption is frequently violated in vivo, where transient drug exposures and dynamic physiological processes prevent equilibrium, leading to potential over- or underestimation of drug effectiveness compared to in vitro results. For instance, classical dose-response curve analyses presuppose equilibrium binding, but kinetic studies of G-protein-coupled receptors demonstrate that non-steady-state dynamics are prevalent, complicating direct translation to biological contexts.^[16]^[31]^[32] EC50 values are highly sensitive to environmental factors like pH, temperature, and downstream signaling alterations, which can shift observed potency without altering the drug's intrinsic affinity for the receptor. Acidic pH environments, common in inflamed tissues or tumors, have been shown to impair μ-opioid receptor signaling and increase EC50 for certain agonists by modulating G-protein coupling. Temperature changes also induce ligand-specific effects; for example, in GABAA receptors, EC50 for GABA increases with rising temperature due to altered channel gating kinetics. Variations in downstream elements, such as receptor density or signal transduction efficiency, further decouple EC50 from binding affinity (Kd), as signal amplification in pathways like those involving G-proteins can amplify or dampen responses independently of initial binding.^[33]^[34]^[35]^[36] Furthermore, EC50 cannot inherently distinguish agonism from antagonism, as it quantifies the concentration producing half-maximal response in a specific assay without specifying the direction of effect—activation or inhibition—requiring additional functional assays to elucidate the ligand's mechanism.^[37]

Practical Applications and Comparisons

In toxicology, EC50 serves as an analogue to the LD50 by quantifying the concentration of a substance that induces a 50% effective response, often for sublethal endpoints such as behavioral changes or physiological impairments in test organisms, enabling assessment of non-fatal toxicity risks.^[38]^[39] This metric is particularly valuable in evaluating chemical hazards where lethality is not the primary concern, allowing for safer regulatory thresholds compared to the LD50's focus on mortality.^[40] In environmental science, EC50 is applied to determine half-maximal effect concentrations for pollutants, facilitating ecotoxicological assessments of aquatic and terrestrial ecosystems. For instance, it measures the impact of pesticides on non-target species like algae or invertebrates, supporting environmental risk evaluations and water quality standards.^[41]^[39] Within biotechnology, particularly enzyme kinetics, EC50 (or the related K50 for cooperative enzymes) quantifies the concentration required for 50% activation or saturation.^[42] EC50 and IC50 are complementary metrics in pharmacology, with EC50 denoting the concentration for 50% activation by agonists, promoting a response like receptor stimulation, while IC50 measures 50% inhibition by antagonists or inhibitors, reducing baseline activity such as enzyme function.^[43]^[44] Both derive from sigmoidal dose-response curves but reflect opposite directional effects—upward for EC50 and downward for IC50—enabling balanced evaluation of therapeutic agents in screening assays.^[16] In personalized medicine, EC50 assessments using patient-derived cells, such as tumor organoids, enable tailored drug sensitivity profiling by measuring agonist responses in individual genetic contexts, as demonstrated in glioblastoma models where EC50 values guide precision therapies within weeks.^[45]^[46] Post-2020 advancements in AI-driven predictions have further enhanced EC50 forecasting in drug discovery, with machine learning models analyzing molecular structures to predict activation potencies.^[47]

References

[1]
50% of what? How exactly are IC50 and EC50 defined? - FAQ 1356
The EC50 is the concentration of a drug that gives half-maximal response. The IC50 is the concentration of an inhibitor where the response (or binding) is ...
[2]
Summarizing EC50 estimates from multiple dose-response ...
EC50 is the concentration of the compound that gives half-maximal response. Dose-response data are typically evaluated by using a log-logistic model that ...<|control11|><|separator|>
[3]
EC50 - an overview | ScienceDirect Topics
EC50, or median effective concentration, is defined as the concentration of a drug, such as amiodarone, that produces 50% of its maximum effect in a given ...
[4]
EC50 - Definition and Relevance | Nanopedia - NanoTemper
In a pharmacological context, this can be the concentration of a drug that is necessary to cause half of the maximum possible effect.
[5]
EC50 - an overview | ScienceDirect Topics
EC50. Half maximal effective concentration. EC50 describes the concentration of a substance that gives half maximal response of a biological pathway.
[6]
Chapter 3: Pharmacodynamics: Molecular Mechanisms of Drug Action
Read chapter 3 of Goodman & Gilman's: The Pharmacological Basis of ... EC50: half-maximally effective concentration. EGF: epidermal growth factor. eNOS ...
[7]
The reciprocal EC 50 value as a convenient measure of the potency ...
In pharmacology, the potency of a compound is expressed as the half-maximal effective concentration (EC50), which refers to the concentration of a drug that ...
[8]
Agonist Potency - an overview | ScienceDirect Topics
Agonist potency is the strength of an agonist in eliciting a response from a receptor, and is an important parameter in drug-receptor pharmacology.
[9]
Agonist binding, agonist affinity and agonist efficacy at G protein ...
These are the Emax (maximal agonist effect), EC50 (concentration of drug that gives a half maximal effect) and the Hill coefficient (an indicator of the form of ...
[10]
IC50 and EC50 | Dose Response - Graphstats Technologies
May 11, 2021 · The EC50 is the drug concentration that produces a half-maximal response. The IC50 is the concentration of an inhibitor at which the response (or binding) is ...Ic50 And Ec50 Definitions · A Case Where Ic50 Is... · Standardized Data Fitting...
[11]
Cell Painting-based bioactivity prediction boosts high-throughput ...
Apr 24, 2024 · Drug discovery campaigns typically rely on high throughput screening ... EC50) of each compound in a given assay. Employing identical cross ...
[12]
Accurate and efficient target prediction using a potency-sensitive ...
Dec 29, 2015 · A small EC50 value corresponds to high potency, i.e., only a small concentration of drug is required for EC50 bioactivity. A molecule is ...
[13]
Quantitative Measurements of Pharmacological and Toxicological ...
Nov 8, 2022 · The half-maximal effective concentration of a compound, EC50, measures the potency of a compound to produce 50% of its maximum effect, either ...
[14]
Affinity, efficacy and potency - Physics, Pharmacology and ...
A drug with a lower EC 50 or ED 50 will have a higher potency, as it suggests that a lower dose of the drug is needed to produce the desired effect. In practice ...Dose--Response Curve · Therapeutic Index · Median Effective Dose
[15]
Pharmacokinetics made easy 10 Pharmacodynamics
Oct 1, 1995 · The ratio adverse effect EC50 /therapeutic effect EC50 gives some measure of the safety of the drug and is called the therapeutic index. Fig. 1 ...
[16]
Dose–Response Curves and the Determination of IC50 and EC50 ...
Oct 1, 2024 · (2) The mathematical form for IC50 is directly derived from the equation for a Langmuir isotherm, as specified in eq 1.<|control11|><|separator|>
[17]
In Vivo Assay Guidelines - Assay Guidance Manual - NCBI Bookshelf
May 1, 2012 · This document is intended to provide guidance for the design, development and statistical validation of in vivo assays residing in flow schemes of discovery ...
[18]
A review for cell-based screening methods in drug discovery - NIH
Cell-based assays are suit to screen targets that are refractory to biochemical purification and can characterize compounds with unknown targets (Fig. 2). In ...
[19]
GPCR-radioligand binding assays - ScienceDirect.com
Radioligand binding assays provide sensitive and quantitative information about guanine nucleotide protein G protein-coupled receptor (GPCR) expression and ...
[20]
(PDF) Guidelines for accurate EC50/IC50 estimation - ResearchGate
Aug 10, 2025 · This article provides minimum requirements for having confidence in the accuracy of EC50/IC50 estimates.
[21]
https://doi.org/10.1021/acs.jmedchem.4c02052
[22]
[PDF] International Union of Pharmacology Committee on Receptor ...
Because the relation between receptor occupancy and response is usually nonlinear, the EC50 generally does not directly measure the equilibrium dissociation ...<|control11|><|separator|>
[23]
Operational models of pharmacological agonism - Journals
The model uses three parameters: agonist-receptor dissociation constant, total receptor concentration, and a parameter defining transduction into effect. An ...
[24]
Quantification of signal amplification for receptors: the Kd/EC50 ratio ...
The gK gain parameter (full agonist Kd/EC50) corresponds to the γ gain parameter of the SABRE receptor model, which includes parameters for Signal Amplification ...
[25]
An overview of pharmacodynamic modelling, ligand-binding ...
Jul 9, 2016 · In general, potency is denoted as the median effective concentration/dose as EC50/ED50/Kd. Efficacy (intrinsic activity) is the ability of a ...<|control11|><|separator|>
[26]
Pharmacodynamics - StatPearls - NCBI Bookshelf - NIH
Jan 29, 2023 · EC50 is the drug concentration at a steady state that produces half of the maximum effect. Hill coefficient is the slope of the relationship ...
[27]
Pharmacodynamics - Basicmedical Key
Mar 10, 2017 · In a system with spare receptors, the EC50 is lower than the Kd, indicating that to achieve 50% of maximal effect, less than 50% of the ...
[28]
Image:Log-concentration vs response curves-MSD Veterinary Manual
Also, the EC 50 of this curve shows that this partial agonist has the same potency (EC 50 = 10) as the full agonist shown in the solid line but a higher potency ...
[29]
https://doi.org/10.1007/s00407-012-0098-5
[30]
https://doi.org/10.1007/s12154-009-0029-3
[31]
The Problems of Applying Classical Pharmacology Analysis to ...
In modern drug discovery, affinity (Kd or Ki) or related measurements (e.g., EC50 or IC50) are determined using high-throughput in vitro assays of ligand–target ...
[32]
Analyzing kinetic signaling data for G-protein-coupled receptors
Jul 23, 2020 · This yields empirical drug parameters, usually the potency (EC50) and a measure of the maximal signaling capacity (Emax). This analysis is ...
[33]
Modulation of μ‐opioid receptor activation by acidic pH is dependent ...
Jul 29, 2019 · Our investigations indicate that low pH selectively impairs μ-opioid receptor signalling modulated by ligands capable of forming hydrogen bonds ...
[34]
Ligand-Specific Temperature-Dependent Shifts in EC 50 Values for ...
Using the EC50 values, we estimated the enthalpy of dissociation between the ligand and the receptor. Furthermore, the technology introduced here is generally ...
[35]
Determining the pharmacokinetics of nicotinic drugs in the ...
Nicotine exhibits a ∼20-fold decrease in EC50 as the pH is increased from 6.0 to 9.0 (Fig. 3 I). Both this pH dependence of the response to nicotine and the ...<|separator|>
[36]
Quantitative live-cell imaging of GPCR downstream signaling ...
The mean ΔF/F0 or ΔR/R0 values (dots) are plotted as a function of ligand concentrations with the fitted curve (gray line) and parameters for EC50 and Hill ...<|separator|>
[37]
Agonist-Antagonist - an overview | ScienceDirect Topics
Agonists produce a response in the system characterized by an EC50 and full (Emax) or partial efficacy. Antagonists themselves do not produce a response; rather ...
[38]
Definition of Toxicological Dose Descriptors (LD50, LC50, EC50 ...
Jun 17, 2016 · LD50 (Lethal Dose 50%) is a statistically derived dose at which 50% of the animals will be expected to die. For inhalation toxicity, air ...Missing: analogy | Show results with:analogy
[39]
Median Effective Concentration - an overview | ScienceDirect Topics
The potency of the toxic compounds is measured by lethal median dose (LD50), median lethal concentration (LC50), or median effective concentration (EC50).Missing: analogy | Show results with:analogy
[40]
Comparative Study on the EC50 Value in Single and Mixtures ... - NIH
The aim of this research was to improve our understanding of human toxicity due to exposure to DMF, MEK, or TOL individually as compared to exposure to DMF-MEK ...Missing: analogy LD50
[41]
Establishment of an EC 50 database of pesticides using a Vibrio ...
The EC50 database allowed classification of the pesticides under study into three categories according to their toxicity: very toxic, toxic and moderately toxic ...Missing: toxicology | Show results with:toxicology
[42]
https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/protein-biology/interrogation-protein-pathways/enzyme-inhibitor-terms-calculations
[43]
A guide to enzyme kinetics in early drug discovery - FEBS Press
Feb 17, 2022 · This also overcomes the excessive reliance on EC50 (half-maximal effective concentration) measurements, which relied on distal reporters, and ...
[44]
What is the difference between EC50 and IC50? - AAT Bioquest
Feb 13, 2020 · While EC 50 measures the concentration of a drug inducing its half-maximal effective response, IC 50 represents the concentration of an inhibitor at which 50% ...
[45]
IC50, EC50 and Kd: What is the Difference and Why Do They matter?
Mar 6, 2025 · IC50 measures inhibition of a function and conversely, EC50 measures activation or induction of a response. Confusing these values can lead to ...
[46]
A Functional Precision Medicine Pipeline Combines Comparative ...
... EC50 values from patient-derived tumor cells within a week [22]. For various cancer types, inclusive of GBM, PDO models have been used for drug screening ...2. Materials And Methods · 2.6. Cell Culture · 3. Results
[47]
High-Throughput Screening of Patient-Derived Cultures Reveals ...
For the purpose of the application of personalized medicine, we wanted to screen patient-derived cells that closely mirror the genotype and gene expression ...
[48]
[PDF] Use of Artificial Intelligence and Machine Learning for Discovery of ...
Mar 15, 2021 · drug discovery (Ballester, 2019; Cartwright, 2020). ML methods map ... of which were tested and 11 found to have EC50 < 10 μM. The five.