The functional properties and specific readouts required of the cell model heavily influence the selection of a cell line for cell culture. The chosen cell lines must also be compatible with the available equipment and the requirements of their specific hazard group.

Primary cells, transformed cells, and self-renewing cells are the three types of cells cultured in the lab.

Primary cells are isolated directly from human tissue, such as fibroblasts obtained from skin biopsies and hepatocytes isolated from liver explants. Because these cell types are good representatives of their tissue of origin, they are frequently used in biomedical and translational research. Handling these cell types, however, is subject to stringent biosafety regulations. Furthermore, because primary cells are finite, they require a constant supply of stocks because their proliferation stops after a limited number of cell divisions and cell expansion is often impossible.

Transformed cells can be produced naturally or through genetic manipulation. While using immortalised cell lines results in a cellular platform with fast growth rates and stable conditions for maintenance and cloning, their manipulated genotype may result in karyotypic abnormalities and nonphysiological phenotypes. Standardised cell lines obtained from human or nonhuman species (– for example, HeLa cells, human umbilical vein endothelial cells (HUVEC) and Chinese hamster ovary (CHO)) on the other contrary are frequently thoroughly characterised and may thus be easier to set up. Self-renewing cells encompass embryonic stem cells, induced pluripotent stem cells, neural stem cells, as well as intestinal stem cells. These cells have the ability to separate into a variety of other cell types, and their ability to self-renew allows for long-term maintenance in vitro. Self-renewing cell types frequently serve as physiologically relevant representatives for in vivo mechanisms.

Cell lines which are obtained commercially, have quality control measures in place to ensure genomic stability and the absence of contaminants. Cell banks and other cell culture laboratories can also be used to obtain cell lines. To ensure clean cultures, the introduction of new cell lines in a lab should always be accompanied by a Mycoplasma PCR test.