Contamination

In a laboratory setting, contamination refers to the presence of an undesired living organism or other chemical pollutant in an experiment. For example, when working with a cell culture it is common to observe contamination with bacteria or fungi, as the environment is optimal for these organisms to thrive. Researchers must follow strict sterile working conditions or use drugs, such as antibiotics, to avoid contamination. The use of antibiotics in cell culture is discouraged, though is still widely used. Antibiotic use can lead to the development of antibiotic resistant strains of microorganisms and the persistence of low-level contamination in cultures. The long-term impacts of antibiotic use in cell culture is yet to be thoroughly investigated, but some studies suggest they can induce changes in gene expression in the cultured cells.