The use of antibiotics creates a false sense of security and allows users to develop poor aseptic techniques. This leads to low-level contamination with partially resistant bacteria occurring but being overlooked for a time. This then leads to cells with undetected contamination being cultured for extended periods of time, increasing the risk that contamination will spread throughout the laboratory and eventually antibiotic-resistant strains of bacteria may develop.
Mycoplasma infections can also occur more easily, as they are often introduced along with contaminants such as bacteria and fungi.
Last but not least, antibiotics are known to have negative effects on the metabolism of eukaryotic cells – more details on this topic can be found in our blog article “Antibiotics in cell culture: friend or enemy”.