MOI Calculator
Calculate viral volume required for a target multiplicity of infection.
About MOI Calculator
Because virions distribute randomly, an MOI of 1 leaves about 37 per cent of cells uninfected rather than infecting all of them. Reaching near-complete infection requires an MOI of around five or more. Assuming MOI of 1 infects every cell is the most common transduction planning error, and the Poisson figure is what corrects it.
Formula
MOI
Volume = (cells × MOI) ÷ titre; uninfected fraction = e^(−MOI)
- MOI
- Infectious units added per cell
- Poisson distribution
- Describes how randomly distributed virions land on cells
Worked example
With the default values below, MOI Calculator returns Viral Volume per Well of 10.0000. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Cells per wellminimum 1
- 200,000
- Target MOIminimum 0.001
- 5
- Viral titreminimum 1 PFU/mL
- 100,000,000 PFU/mL
- Number of wellsminimum 1
- 12
Results
- Viral Volume per Well
- 10.0000 uL
- Infectious Units per Well
- 1,000,000 PFU
- Total Viral Volume
- 120.000 uL
- Total Infectious Units
- 12,000,000 PFU
- Predicted Uninfected Cells
- 0.6738%
Step by step
- 1Values used
- 2MOI
- 3Viral Volume per Well= 10.0000 uL
- 4Infectious Units per Well= 1,000,000 PFU
- 5Total Viral Volume= 120.000 uL
- 6Total Infectious Units= 12,000,000 PFU
- 7Predicted Uninfected Cells= 0.6738
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is MOI calculated?
Volume = (cells × MOI) ÷ titre; uninfected fraction = e^(−MOI) Because virions distribute randomly, an MOI of 1 leaves about 37 per cent of cells uninfected rather than infecting all of them. Reaching near-complete infection requires an MOI of around five or more.
Why does MOI matter?
Assuming MOI of 1 infects every cell is the most common transduction planning error, and the Poisson figure is what corrects it.
What values do I need to enter?
This calculator takes 4 inputs: Cells per well, Target MOI, Viral titre, Number of wells. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.