I have some human epithelial cancer cell lines that tend to clump after trypsinization. The clumps are usually made up of 4-8 cells and this makes the counting difficult and determining how many cells to seed even more confusing. To trypsinize my cells, I wash my cells once with 1X PBS, add trypsin then place at 37 for 5-10 minutes. The cells start to release in clumps without tapping. I add complete media to mix and break up the cells as much as possible. During cell counting, a majority of these cells are in clumps in the hemocytometer.
Should I try to count all the cells in the clump as individual cells or treat the clump as one cell? I.e. clump of 4 cells as one cell or clump of 4 cells as 4 cells? When I seed the cells, the clump will settle as one cell which is why I thought maybe counting the clump of 4 cells as one cell.
Are some cells just prone to clumping? I have a couple a few lines that do this and the rest do not.
Any method or technique to overcome clumping? Reagent to use, needle and syringe break up clumps, different method of trypsinization? Please help!