Cell Viability Calculator
Determine the health and percentage of viable cells in a population. Essential for checking cell health prior to transfection, freezing, or subculturing.
Viability Counts
Input counts of live and dead cells.
Cell Viability Percentage
* A healthy culture typically has viability above 90%.
Assay Timing
When using Trypan Blue exclusion, count cells within 3-5 minutes of mixing.
Common Cell Viability Assays Comparison Matrix
| Assay Name | Mechanism / Target | Readout Method | Key Advantage |
|---|---|---|---|
| Trypan Blue Exclusion | Cell membrane integrity | Brightfield Microscope / Automated Counter | Fast, highly cost-effective |
| MTT / MTS Assay | Mitochondrial reductase activity | Absorbance (570 nm) | High-throughput 96-well screening |
| Calcein-AM / EthD-1 | Esterase activity + DNA binding | Fluorescence Microscopy / Flow Cytometry | Distinguishes early apoptosis |
| ATP Luminescence (CellTiter-Glo) | Intellular ATP quantity | Luminometer | Ultra-sensitive linear dynamic range |
Calculation Methodology & Equations
Viability Percentage Formula
Measures the proportion of membrane-intact viable cells.
Dead Cell Percentage
Calculates non-viable cell percentage in suspension.
Frequently Asked Questions
What is a healthy cell viability percentage? ▼
For standard tissue culture, cell viability above 90% is considered optimal. Viability below 80% often impairs transfection efficiency, differentiation potential, or cryopreservation post-thaw recovery.
How does Trypan Blue dye exclusion work? ▼
Trypan Blue is a membrane-impermeable diazo dye. Intact cell membranes exclude the dye, leaving live cells clear/bright. Dead cells with compromised membranes stain dark blue.
Why must Trypan Blue counts be read quickly? ▼
Viable cells eventually internalize Trypan Blue via endocytosis after prolonged incubation (>5–10 min), causing false-positive blue staining and underestimating viability.
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