Hi Everyone

First year PhD student in London here, I'm new to Caco-2 cells.

I have two issues that are bugging me. Does anyone have any advice on how I can navigate these problems?

The first one, as shown in the first image, where cells seem to clump together in a wall like structure, and there are cells growing on one side but none on the other side of this 'wall'. This is super annoying because I seed the cells and let them grow for a week, only to find that the cells on one side of the plate have died or disappeared so I essentially waste a week and media.

The second one, are the black rod like structures bacteria? I'm treating my cells with media in the absence of antibiotics for a gentamicin protection assay for 24 hours but normally, I do use pen-strep 1%. Cell viability in the potentially infected regions appears to be severely limited. However, the media is not cloudy?!

Thanks so much!

Pranaya