Studying living organisms is identified as biological cultures. Biological cultures are categorised into several types; organ culture, tissue culture and cell culture. A cell culture means a biological culture of cells of multi-cellular eukaryotes. It is a cultivation of cells, which are derived from a multi-cellular eukaryote and has grown under controlled conditions in a laboratory and not in their natural environment. These cells are usually animal cells.

Cell cultures, like live cell lines, are essential in studying and producing biological products as this is s much safer way to test the product, as opposed to doing the experiment directly on animals, which would be unethical. This has become a way of manufacturing therapeutic products; vaccines, synthetic hormones, anticancer agents, immunobiologicals and more.

One of the researches cell lines contribute towards, is the never ending battle against cancer. Most available tumor cell lines were established using the culture method. Some of the first cell lines that were generated and showed dramatically different behaviour, were the small-cell lung cancer cell lines. They were growing as floating spheroids in a liquid medium. On the other hand, the three-dimensional growth characteristic of small-cell lung cancer lines showed a different result; which was their exclusion from large tumor cell line panels growing in two-dimensional mode.

Recently, some established cell lines which are genetically authenticated, as derived from specific individual cancer patients, were banked with low passage. They were also characterized as a confirmation as an expression to some specific and very important features; drug sensitizing mutations for instance, as well as other characteristic genetic changes. Those cell lines might have a bigger clinical relevance. A recent study showed that cell lines which harbour EWS−FLI1 gene translocation, has supported the identification of a clear characteristic sensitivity of this tumor to PARP inhibitors.

Studying cell cultures is quite vital and beneficial to the research on disease and discovery of new drugs.