Subculture (biology)

Once nutrients are depleted and levels of toxic byproducts increase, microorganisms in culture will enter the stationary phase, where proliferation is greatly reduced or ceased (the cell density value plateaus).

Subculture into a larger volume of growth medium is used when wanting to increase the number of cells for, for example, use in an industrial process or scientific experiment.

In the case of plant tissue cells, somaclonal variation may arise over long periods in culture.

These cell types can be subcultured by simply taking a small volume of the parent culture and diluting it in fresh growth medium.

For subculture, cells may be detached by one of several methods including trypsin treatment to break down the proteins responsible for surface adherence, chelating calcium ions with EDTA which disrupts some protein adherence mechanisms, or mechanical methods like repeated washing or use of a cell scraper.

A line of twenty T175 cell culture flasks filled with approximately 40 mL of red cell culture medium
Line of T175 cell culture flasks containing red cell culture medium