The means with which to encourage and to sustain the growth of living cells when isolated from their host tissue has long played an important role in medicine, and has applications in both the diagnosis and the treatment of diseases. The earliest attempts to develop specialised cell culture media can be attributed to the pioneering microbiologists, Pasteur and Koch. In practice, it is the Frenchman who is accredited with being the first to demonstrate that microscopic living organisms in our surroundings were the cause of some diseases, and also with having developed the first nutrient mixture capable of supporting the growth of those microorganisms artificially.

His mixture consisted of yeast, ash, sugar and ammonium salts which, together, provided the carbon, nitrogen and vitamins necessary for bacterial growth. His experiments revealed the fact that certain ingredients were able to either encourage or supress the growth of specific bacteria, leading to the development of specialised mixtures for the differential isolation and identification of individual bacterial species.

Then, as now, these growth mixtures were produced either in the form of a liquid nutrient broth, or a similar mix solidified by the addition of gelatine. Later, a water-soluble polysaccharide extracted from red-purple seaweeds, and known as agar-agar, became the solidifying agent of choice, while the ability to liquefy gelatine was found to be a property of certain bacterial species, and so provided microbiologists with a simple test with which to identify them.

The role of cell culture media was to take a dramatic turn with the first attempts to cultivate living tissues. At about the same time as Pasteur was busily engaged in developing his nutrient broths, Sydney Ringer, an English physiologist, used a warm solution composed of sodium, calcium, potassium and magnesium salts to maintain the beating of an animal heart that had been removed from its body. Similar experiments performed on embryonic tissue from chickens, and later, involving the propagation of viruses in living cells, would first make possible the development of the polio vaccine, and later, play an invaluable role in the development of new medical technologies, such as stem cell therapy.

To maintain the life and growth of an isolated cell line requires not only the use of specialised culture media, but specialised physical conditions are also necessary. Although the precise needs may vary quite considerably between strains, typically, mammalian strains need to be maintained at a temperature of 37°C, and thrive best in an atmosphere of 5% carbon dioxide and a humidity level of around 95%.

As is the case with bacterial cultures, the specific nutrient requirements can also tend to vary, and will depend upon the particular cellular type to be propagated. Clearly, the conditions for optimum growth are crucial, and for this, all of the equipment and nutrient materials employed need to be of the highest quality, in order to ensure reproducible results. For such assurances, the use of commercially-prepared cell culture media is far preferable to relying on time-consuming and error-prone, in-house preparations.

For guaranteed quality and performance, most medical diagnostic and research establishments in South Africa now rely exclusively on IEPSA for tried-and-tested, world-class equipment, reagents and laboratory disposables.

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