Zoom in on microorganisms

Genetic engineering to the rescue of diabetics

How do they actually make insulin?ZoomZoom
© Armand-Frappier Museum

One form of diabetes is due to a physiological malfunction, namely the inadequate production of the hormone known as insulin. Insulin allows the body's cells to absorb glucose, which they use as food. Diabetics often must receive insulin injections. Today, the insulin which so many diabetics need is produced in large quantities by microorganisms; this type of insulin is known as recombinant insulin. Prior to the use of microorganisms, insulin similar to human insulin was obtained from dogs, pigs, and cows and subsequently purified. This technique is still used today.

As the number of cases of diabetes continued to increase (currently, more than two million Canadians are diabetic), the need to find a way to produce large quantities of insulin inexpensively also grew. Genetic engineering techniques harness microorganisms for this purpose. Since 1983, insulin has been produced commercially on a large scale using the E. coli bacterium, and in 1987, a process based on the yeast Saccharomyces cerevisiae was introduced. Thanks to these advances, diabetics can lead normal lives by injecting small quantities of this hormone.