I am 3 months into a new job and have been isolating/ immortalizing primary mouse intestinal fibroblasts by serial passage.
Up until P6-7 all was well till I noticed these (see attached images) stringy contaminants.
Protocol - ... PBS wash x2 while changing medium (FBS, Pen/Strept, 2-3 days), freeze cells (stock) after every 2 passages. Spli
Cells started dying overnight.
I discarded my precious stock of near-immortalised cell lines plus medium and received new cells from a colleague.
Noticed same objects after 24h.
Cultured my fresh medium, and trypsin stock - there they were!
My big challenge is what to do next.
I have frozen vials that I can re-propagate and continue to immortalise but I`m so afraid the contaminants will reoccur.
The images are attached.
Please help as I don`t know what else to do and this has given me insomnia for days now + I need this job. I've read through the posts here and am uploading the images.
Thanks in advance!