Primary Cell Culture
Primary cells are mammalian cells that are directly harvested from living human or animal tissues. Unlike stem cells, primary cells are typically terminally differentiated, meaning they closely resemble the tissue from which they were isolated. This makes them highly representative of normal biological systems, especially when compared to cancer cell lines, which may be less predictive due to the alterations associated with cancer biology. Primary cells are valuable models for studying a range of physiological and pathological conditions. Common primary cell types include epithelial cells, endothelial cells, keratinocytes, melanocytes, fibroblasts, osteoblasts, myocytes, and hepatocytes, each with distinct roles and characteristics that reflect the diverse functions of human and animal tissues.
Overview
How Primary Cells Differ from Immortalized Cell Lines
Like cell lines derived from tumors or immortalized by other methods, primary cells from human or animal sources provide a method for modeling biological systems. Because they are typically viable for fewer doublings, primary cells are less susceptible to the loss of tissue-specific traits that can characterize cells cultured over long periods of time and repeated passages in vitro. Primary cells may be documented with donor characteristics, including age, gender, and disease state where applicable, and may therefore prove useful models for the development of personalized medicine approaches.
Sourcing and culturing primary cells
Research institutions associated with hospitals may have access to primary tissues and cells. Primary cell suppliers offer cell lots from individual donors or cells pooled from multiple donors. Reputable suppliers or patient collection protocols should include documentation demonstrating ethical oversight for the isolation of cells from human donors, as well as validation of cell type. Primary cells differ from mammalian cell lines in that they are generally more fastidious, requiring extra nutrients, particularly when cultured in media that is low in serum or serum-free. These additional, defined nutrients include cytokines and growth factors.