Hello sweta, even i am working on hepg2 and working on cytotoxicity. We had similar issues, but got rid of it by using the cells from similar phase of cell- cycle everytime while experimenting..
Thanks Harita. I was using cells of similar passage number i.e. passage 4. I do not let them to get "too confluent" before passage and also tried my experiments on cells thawed from liquid Nitrogen, but again getting reproducibility issues. I am not sure how to get cells from similar phase. Could you please explain how to get cells from same phase.
Well we have checked the phase by repeatatively doing facs at similar confluence, more or less 70% confluence with hepg2 gives u log phase which is the best phase for such studies