Understanding of Cell Sample Dilution Factor

The cell sample dilution is an important factor determining accurate cell concentration with the cell counter. The cell counting algorithm can detect the cells within the specific counting range of 5 × 10⁴ to 1 × 10⁷ cells/mL. If the number of cells is too high, diluting your cell suspension could help you to stay within the counting range of the cell counter. This article provides an example calculation for the cell dilution factor and describes what information needs to be entered when using diluted samples.

Example calculation:

The image below provides an example calculation of the dilution factor. The cells are first diluted 4 times with a dilutant and additionally mixed with Trypan blue for a viability measurement. On the left side, the dilution of 1:4 is shown, and on the right side, the 1:1 dilution with trypan blue is depicted. The final dilution factor is calculated as ((10 + 40) / 10) x 2 = 10.

The image below shows a visual representation on how to enter the sample dilution in the application following the dilution of 1:4 and 1:1 dilution with trypan blue. The dilution factor is automatically calculated by the software.

Special considerations for viability dye: 

When using a viability dye, such as trypan blue, the sample is typically diluted by a factor of 2 or in a 1:1 ratio. In this case, the final dilution factor should be multiplied by 2 to account for the additional dilution from the viability dye, as illustrated above.  In case you are using trypan blue with a 1:1 dilution but have not further diluted your cell suspension, you should specify the Sample Dilution as "No" and Trypan Blue to "Yes (1:1)". The dilution factor will then automatically be updated to 2.