In biomedical research, if one is ever asked about the primary component of a clinically relevant scientific study, the go-to term is cell culture. Cell culture is an indispensable fraction of biomedical research which forms the first step towards quality in vivo experiments. These provide a platform for controlled and biologically-significant experiments on various cellular pathways and functions.
Primary cells are taken directly from the tissue of origin and then maintained in culture under optimized conditions. They exhibit characteristics that are closer to the in vivo state and therefore provide a good model for studying cell physiology and pathways. The most common primary cell types used in research are epithelial cells, fibroblasts, endothelial cells, hematopoietic stem cells, and mesenchymal stem cells. When primary cells undergo a genetic transformation, either virally or chemically induced, they become immortalized secondary cell lines.
Researchers extensively use cell lines for their cell culture studies as they are highly proliferative and easier to maintain in culture. But reports provide evidence of cell lines showing altered morphology, genotypically or phenotypically, with respect to their tissue of origin. In contrast to cell lines, primary cells are directly isolated from the tissues and therefore retain original morphological characteristics besides maintaining the functionality of various marker proteins. Moreover, the use of primary cells evades the ethical objections against animal experiments in vivo and helps in procuring reliable data for assessment before human experiments. The various applications of primary cell culture are 3d cell culture, cancer research, virology research, drug screening, vaccine production, tissue replacement, genetic engineering, and stem cell therapy.
The major limitation of using primary cell culture is that primary cells have a limited lifespan and stop dividing after a few passages. But even though primary cells need more expertise to maintain and have a limited passage potential, the research conducted using primary cells are closer to mimic bio-physiological conditions and can add a better angle to pre-clinical trials.