The NucleoCounter® SP-100™ concept offers determination of cell viability in addition to the total count of cells in the sperm sample. Determination of viability is based on the “PI-exclusion” method (the principle is presented below).

Measuring Sperm Cell Viability

Cell Viability (the membrane integrity) can be measured with the NucleoCounter® SP-100™ in a two-step procedure by measuring the difference between the total cell count and the non-viable cell count (see the figure below).
When a sample is diluted with Reagent S100 a lysis of the viable cell membrane takes place rendering all the cell nuclei susceptible to staining with propidium iodide (PI) resulting in a total cell count.

Non-viable cells diluted with PBS (Phosphate Buffer Saline) are however permeable without treatment and are therefore stained directly with PI, resulting in a non-viable cell count. The difference between the two measurements provides the viable cell count – or % Viability.