In order to determine the number of cells per ml, you simply count the total number of cells in ten primaries and multiply by 2 (the dilution factor when using trypan blue) and 1000 (the conversion factor to convert from cell per ul to cells per ml).

For example, in this image, the purple cells are dead and not counted, and the white cells are living.

There are 14 living cells, and 2 dead cells in the primary above.

You would then count the cells in 9 more primaries, and the running total of living cells is what you would multiply by 2000. This gives you the concentration of cells per ml.

The following is a real photo of cells on a primary:

In this case, there are approximately 25 living cells, and zero identified dead cells.

Learning Objectives:

- 1.4 - Count cells using a hemocytometer.