Hi everyone.

We are mainly a cell culture lab and facing issues with a lot of contamination. We've had black swimming dots as the can you see in the video attached in our cell culture . The seem to be a very resilient kind and survive different types of decontamination processes of the biosafety hoods and the incubator. We've also checked the cell lines that we have for contamination but don't have any in the cell lines/batch of cells.

The contamination grows in media at room temperature if kept overnight as well.

We see it the cell culture flasks in the background/places where the cells are not growing. But the cells don't die immediately.

We see the cells growing very slowly but no change in color of media.

If anybody has any experience or see something similar in their cell cultures please let me know through the comments

Thank you