Trypsinization is the process of cell dissociation using

trypsin Trypsin is an enzyme in the first section of the small intestine that starts the digestion of protein molecules by cutting these long chains of amino acids into smaller pieces. It is a serine protease from the PA clan superfamily, found in the d ...

, a

proteolytic Proteolysis is the breakdown of proteins into smaller polypeptides or amino acids. Uncatalysed, the hydrolysis of peptide bonds is extremely slow, taking hundreds of years. Proteolysis is typically catalysed by cellular enzymes called proteases ...

enzyme which breaks down proteins, to dissociate adherent cells from the vessel in which they are being cultured. When added to a cell culture, trypsin breaks down the proteins that enable the cells to adhere to the vessel. Trypsinization is often used to pass cells to a new vessel. When the trypsinization process is complete the cells will be in suspension and appear rounded. For experimental purposes,

cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...

are often cultivated in containers that take the form of plastic flasks or plates. In such flasks, cells are provided with

growth medium A growth medium or culture medium is a solid, liquid, or semi-solid designed to support the growth of a population of microorganisms or cells via the process of cell proliferation or small plants like the moss '' Physcomitrella patens''. Differ ...

comprising the essential nutrients required for proliferation, and the cells adhere to the container and each other as they grow. This process of cell culture or

tissue culture Tissue culture is the growth of tissues or cells in an artificial medium separate from the parent organism. This technique is also called micropropagation. This is typically facilitated via use of a liquid, semi-solid, or solid growth medium, su ...

requires a method to dissociate the cells from the container and each other. Trypsin, an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

commonly found in the

digestive tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans an ...

, can be used to "digest" the

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

s that facilitate adhesion to the container and between cells. Once cells have detached from their container it is necessary to deactivate the trypsin, unless the trypsin is synthetic, as cell surface proteins will also be cleaved over time and this will affect cell functioning. Trypsin is inhibited by serum that provides the divalent cations like calcium and magnesium which plays a role in both intra and intercellular signalling process i.e. forming CAMs, so serum is usually added to the container once cells have detached - this can be confirmed by observation under a microscope. Trypsinization is often done to permit passage of the cells to a new container, observation for experimentation, or reduction of the degree of confluency in the flask by removal of a percentage of the cells.

References

{{Reflist Cell culture