Primary cells normally can only undergo a limited number of cell divisions in culture, and then enter replicative senescence where they can no longer divide. Scientists need to frequently re-establish fresh culture from tissues, which can be tedious and can add to variability from one preparation to another. Immortalized cells derived from primary cells can surpass normal cellular senescence and have extended replicative capacity. Immortalized cells are highly useful for research in cell biology as they are easier to culture and maintain, thus enabling scientists to use the same consistent cells through research projects for longitudinal studies.

Several methods exist for immortalizing mammalian cells in culture conditions. Simian virus 40 (SV40) T antigen can induce Telomerase activity in the infected cells and has been shown to be the simplest and most reliable agent for the immortalization of many different cell types. The most recently discovered approach to cell immortalization is through the expression of Telomerase Reverse Transcriptase protein (TERT). This approach is particularly useful for cells that are most affected by telomere length, including many human cell types. TERT is usually silenced in most somatic cells. These cells can avoid replicative senescence by maintaining sufficient telomere lengths when hTERT is exogenously introduced. However, over-expression of hTERT in some cell types (especially in epithelial cells) fails to induce cell immortalization.

Alstem provides both SV40 and hTERT cell immortalization kits, please see below for ordering information.