Cytology. Cell density can be measured with the following methods:
1. grams of wet weight per liter of sample (the wet cells are weighed),
2. grams of dry weight per liter of sample (the cells are dried before weighing),
3. number of viable cells per ml (counting the cells after successively diluting the original sample and plating on a Petri dish),
4. number of viable and dead cells per ml (direct counting in a chamber),
5. number of viable and dead cells per ml (using a coulter counter).