Complex sentence: A cell-counting assay may determine the number of living cells, the number of dead cells, or the ratio of one cell type to another, such as numerating and typing red versus different types of white blood cells.
Split into simpler sentences: A cell-counting assay, may determine the number of living cells, the number of dead cells, or the ratio of one cell type to another. This is for example applied to numerating and typing red versus different types of white blood cells.