For the cell culturist, two types of contamination require careful monitoring and constant vigilance: the contamination of cell cultures with microbiological organisms and the contamination of one cell line with another. Both forms of contamination are extremely prevalent and cannot be underestimated. Neither type can be eliminated, only controlled and managed to minimize the possibility of occurrence. Contamination consequences can range from minor inconvenience (a flask of cells becoming contaminated with bacteria) to a major disaster (published results that may be invalid owing to cross-contamination of one cell line with another). Other types of contaminants, such as chemical contamination, may also cause problems (e.g., deposits of disinfectants or detergents on glassware; residues, impurities, and toxins in water, media or sera), but the common recurring problems are likely to be biological in origin.
