Morphology of cells is fine. No change in media color, pH or proliferation rate. we are observing black debries+ some thread like structure. They are not affecting cell's morphology. What could be the reason?
Unless you are seeing morphological changes (mycoplasma), active filament growth (micelium), or growth of bacterial colonies, I would not be convinced that you have contamination based of the images.
Unless you are seeing morphological changes (mycoplasma), active filament growth (micelium), or growth of bacterial colonies, I would not be convinced that you have contamination based of the images.