Viability, Proliferation and Cell Cytotoxicity Assays
We develop and perform cell viability and cytotoxicity assays to evaluate the effect of compounds, drugs, and biological products on living cells, generating quantitative and reproducible data for toxicity, efficacy, and potency studies.
- Cell viability and cytotoxicity
- Dose–response studies
- IC50 / EC50 determination
- Method development and optimization
The assays are adapted to the sample type, cell line, and study objective, allowing the assessment of proliferation, metabolic activity, and biological response under controlled experimental conditions.
The cellular response is translated into quantifiable parameters that facilitate comparison between compounds, formulations, concentrations, and assay conditions.
We generate functional evidence to support toxicity studies, potency evaluation, formulation selection, and comparability, with designs tailored to each cellular model and product development objective.
What are cell viability assays?
A cell viability assay measures the ability of cells to remain metabolically active after exposure to a treatment.
The signal obtained is proportional to the metabolic activity of living cells. These assays allow the determination of:
- Cell viability (%)
- Cytotoxicity
- Cell proliferation
- Dose response
The challenge of cell viability assays
Improper optimization can directly affect result interpretation. Cell viability assessment requires:
- High sensitivity and reproducibility
- Control of experimental conditions
- Compatibility with different matrices
- Appropriate method selection (MTT vs resazurin)
Robust and reproducible viability and cytotoxicity assays
All our assays are performed under a GxP-aligned approach and regulatory requirements. At Netpharmalab, we implement cell viability assays in 96-well plates, with:
- Standardized protocols
- Positive and negative controls
- Colorimetric or fluorescent readouts
- Advanced quantitative analysis
Main applications of cell viability and cytotoxicity assays
- Toxicity evaluation of biologics and formulations
- In vitro potency assays
- Preclinical cytotoxicity studies
- Cell proliferation assessment
- Optimization of culture conditions
- Comparison between compounds, batches, or formulations
What does our service include?
- Cell viability assays (MTT / resazurin)
- Cytotoxicity and proliferation assessment
- Dose–response studies
- IC₅₀ / EC₅₀ determination
- Adaptation to different cell lines
Methodology: Resazurin and MTT
Resazurin (AlamarBlue):
- Reduction by viable cells → fluorescent/colorimetric signal
- Non-toxic method → allows repeated measurements
- High sensitivity
MTT:
- Reduction to formazan crystals by viable cells
- Widely validated method
- High robustness and reproducibility
Assay workflow
- Cell seeding at optimal density
- Treatment with drugs or experimental conditions
- Addition of reagent (MTT or resazurin)
- Controlled incubation (37 °C, 5% CO₂)
- Microplate reading (absorbance or fluorescence)
- Data analysis:
– % viability
– Dose–response curves
– IC₅₀ / EC₅₀
Regulatory compliance
Our assays comply with:
- Good Bioanalytical Practices (GxP)
- 21 CFR Part 11 (data integrity)
- Standardized SOPs for all processes
- IQ/OQ of equipment (incubators, readers, hoods)
Frequently Asked Questions (FAQ)
- What is the difference between MTT and resazurin?: MTT generates an insoluble product (formazan), while resazurin allows non-destructive and repeated measurements.
- What types of cells can be used?: Adherent and suspension cells, including standard cell lines and specific models.
- What are IC₅₀ or EC₅₀?: They are parameters indicating the concentration of a compound required to inhibit or activate a response by 50%.
- Are these assays valid for regulatory studies?: Yes, especially in preclinical phases and pharmaceutical development support studies.
- Can different formulations or batches be compared?: Yes, these assays are ideal for comparing efficacy and toxicity between samples.
Request more information about our biological product analysis services
GMP