I am an undergraduate physics student working in a biophysics laboratory, and recently on the job I have started culturing cells. We need the cells in suspension for reasons I can't disclose but the important part is that I am having some difficulties in the trypsinization process. The main problem is that when I want to count the cells. Basically, after I add the 2mL of trypsin to the plate (polystyrene I think) and let it sit for a couple minutes, I dilute the tryp with some culture medium (8mL). Then I transfer this suspension to a conic tube which is where I count from. BUT, I have noticed that the concentration is really low (around 8-16 *10^4 cells/mL) and I took a look at the plate and I can see that there appears to be a bunch of cells still on the plate! And they all seem to be bunched up near one of the edges of the plate which is probably due to the fact that I tip the plate to get all the medium up without any air. Any biologists out there that do this regularly that can give me some tips? I'm the only person in the lab that does this and they're kind of putting a lot of pressure on me ugh. BTW, These cells are HeLa cells, the trypsin medium is TryPLE, and I do wash the cells with PBS before I trypsinize. I know for a fact that the cells are balling up when the trypsin is added, but I just can't seem to transfer them adequately.