Getting some culture
Many types of cell are grown in the lab for research
Many kinds of cells can be kept alive outside the body in a laboratory dish. If they grow and reproduce, you have a cell culture. Many cell culture ‘lines’ (or types) are used in research. To some extent, they can substitute or complement the use of whole organisms, particularly for toxicity or drug effects. However, cultures usually consist of a monolayer (a layer one cell thick) of a single type of cell, not the mix of cells found in real tissues. They also lack the three-dimensional structure of tissues and organs, which have defined shapes and support their cells in carefully ordered arrangements.
New techniques have enabled the development of ‘organoids’ – 3D organ-bud growths, which have been used to mimic brain structure. This has been used to understand cell movement during development and the effect of drugs on brain regions.
Successful tissue culture is as much art as science. Cells need carefully controlled conditions to grow, including the right temperature, gas mix and growth factors in the medium they grow in. The longest-lived cultures are often derived from cancer cells, which have found ways to override normal controls on cell division. Such cell lines have to be checked continually. The cancerous cells may go on changing, as they do in a tumour that’s still in the body. It is also easy for cultures to become contaminated by other cells. If this goes unnoticed, experiments may not be testing what the investigators think.