Biochemical Techniques and Instrumentation

6.3.3.1. Isolation of cells

Cells are isolated from tissues in several ways. Blood cells can be easily purified but only the white cells can be grown by cell culture.

Mononuclear cells can be released from soft tissues by enzymatic digestion with the help of enzymes such as collagenase, trypsin or pronase. Soft tissue pieces can be placed in growth media, and the cells that grow out are available for culture. This method is known as "explant culture".

Cells that are cultured directly from a tissue are known as "primary cells". Most primary cell cultures have limited lifespan. After a certain number of population doublings, these cells undergo the process of senescence and stop dividing but retain the viability.

Random mutation or deliberate modification such as artificial expression of the telomerase gene can help an immortalised cell line to acquire the ability to proliferate indefinitely.