Can someone help me identify the contamination growing in human cancer cell lines?
They are small dots-like organisms, that grow slowly when I increase the antibiotic concentration (2X) but do not get eliminated. They do not grow in nutrient broth and LB.
I would appreciate it if anyone who faced similar issues could help me overcome such contamination.
Hi Mrityunjay Tyagi ,
Most bacteria will appear as black dots in the background, and will probably generate turbidity. Also, the dots are too small to be fungus/yeast.
Cell debris could be a possibility. This could explain the absence of growth in nutrient broth/LB but more generation of these dots with 2X antibiotic (if your original cells are sensitive to antibiotics)
Mycoplasma contamination is another possibility. Here is a post for detecting and eliminating mycoplasma contamination.
https://blog.cellsignal.com/mycoplasma-contamination#:~:text=Plasmocin%2C%20one%20of%20the%20most,if%20the%20treatment%20was%20successful.
More info here:
https://unclineberger.org/tissueculture/contaminant/
https://www.thermofisher.com/us/en/home/references/gibco-cell-culture-basics/cell-culture-protocols/use-of-antibiotics-and-antimycotics.html
Perhaps, these threads on the same topic could be of of help.
https://www.researchgate.net/post/Can_anyone_identify_what_these_small_particles_are_Is_this_normal_for_cell_culture
https://www.researchgate.net/post/What_kind_of_cell_culture_contamination_is_it
If you suspect contamination, it is wise to discard these cells soon to avoid more propagation. Definitely, do not use the contaminated cells for studies but start with fresh cells.
Good luck :)!
