The contaminations in the cell culture can be identified through changes that can
be identified with the naked eye (visible) and changes that cannot be seen with
naked eyes (invisible).
The visible changes include
- pH alteration- A change in the pH can result in change in color
of the medium.
- Fungal infection- This can occur as a change in the turbidity
or colonies of fungal organisms.
The above changes cannot be reversed due to which the culture cannot be used and
has to be discarded.
Invisible changes mean that the mixture is contaminated, mostly due to mycoplasma.
(Mycoplasmas are a genus of bacteria that lack a cell wall and are mostly resistant
to beta-lactum antibiotics). These contaminations can spread rapidly to other cultures
and are hard to eradicate. This form of contamination can cause.
- Chromosomal abnormalities-This is a condition in which there
are abnormal number of chromosomes such as an extra copies or missing copies of
a specific chromosomes or presence of chromosomes with missing or extra pieces.
- Cell transformation- change of structure of the cell- modification
of genome.
To avoid this form of contamination, it’s mandatory to perform routine screening
of all the organisms in cell cultures.