Cell seeding density calculator
From your counted suspension to the volumes for a plate, with spare wells so the last one is not short.
Free, no account needed. Nothing you type is sent anywhere or stored — the arithmetic runs in your browser.
Inputs
Results
Cell suspension to take
1.3mL
- Wells to prepare for
- 26
- Cells needed
- 1300000
- Medium to add
- 11.7mL
Spare wells, for the same reason as a master mix
Pipetting loses a little at every transfer, and a suspension made for exactly the number of wells runs out at the end of the plate. The spare wells are not waste — they are what stops the last column being thin.
Cells per well only means something with the plate named
Seeding density is often published per cm², and well areas are not obvious: a 6-well well is about 9.6 cm², a 12-well about 3.8, a 24-well about 1.9, a 96-well about 0.32. Taking a cells-per-well figure from a paper that used a different format is how a confluent plate becomes a sparse one.
If your protocol gives a density per cm², multiply by the area of the well you are actually using before putting a number in here.
Count live cells, not cells
A haemocytometer count that includes dead cells over-states the suspension, so every well is seeded low — and the plates that look worst are the ones where viability was worst, which reads as a treatment effect. Use the live count, and remember the dilution factor if you diluted into trypan blue.