Hello everyone,

I have an issue relating to hIPSCs maintanance after first passage. After a 2 days post the first passage I began seeing many rounded, bright spots on the cells seeded in a 6 well plate dish. As they were not fully removed after media change and they increased in number per day I suspected it may have been yeast contamination, so I started treatment with low 0.25ug/ml of amphoterin B. All media contains 1% pen/strep. They have been treated for 2 days but now I believe it may have been high cell death that i cannot explain. i undertsand that amphoterin B inhibits cell proliferation but the issue began before treatment. From the images that i attach now (before and after media change at 2 days post treatment) could someone give me their insight regarding if it is cell death or contamination and why or how to tackle the issue? The cell culture is not getting confluenced at the rate expected although it is true that that is very variable among hIPSCs cell orginin.

Thank you for your time, all insights are appreciated!