Cell Therapy & Gene Therapy Equipment worked example

Cell Expansion Yield at 58% minimum acceptable expansion yield: a worked example

This worked example runs the cell expansion yield numbers for a tougher week than the baseline: 58% minimum acceptable expansion yield instead of the typical 80%. Calculate harvested viable cell yield against the target cell count for a patient batch, donor lot, or expansion run.

The inputs for this scenario

  • Harvested viable cell count: 8,500,000,000 viable cells (held at the documented default)
  • Target viable cell count: 10,000,000,000 viable cells (held at the documented default)
  • Minimum acceptable expansion yield: 58 % (the input this scenario stresses; the baseline uses 80)

Working through the calculation

  • The calculation starts from the formula this tool documents: Cell expansion yield = harvested viable cell count ÷ target viable cell count × 100.
  • Cell expansion yield works out to 85 % at these inputs, and this is the headline figure for the scenario.
  • Yield gap to minimum target works out to -27 points at these inputs.
  • Harvested viable cell count works out to 8,500,000,000 count at these inputs.
  • Target viable cell count works out to 10,000,000,000 count at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where minimum acceptable expansion yield sits at 80% and the headline result is 85 %, this scenario lands almost exactly on the baseline at 85 %.
  • Use it at harvest for every lot to confirm the culture met its viable-cell target and to flag underperforming runs for deviation review. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Cell expansion yield: 85 % (headline result)
  • Yield gap to minimum target: -27 points
  • Harvested viable cell count: 8,500,000,000 count
  • Target viable cell count: 10,000,000,000 count

Run it with your numbers

  • To rerun this with your own numbers, open the live Cell Expansion Yield calculator, set minimum acceptable expansion yield to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.