With its latest doodle, Google celebrates the 125th birthday of Sir Frederick Banting, who together with Charles Best, pioneered the use of insulin in the treatment of diabetes.

The doodle features a bottle of insulin in place of the second letter 'o' in Google and also an image of the digestive tract, which was key to Banting's theory that the pancreas' secretion held the key to the treatment of diabetes. World Diabetes Day coincides with Banting's birthday on 14 November.

According to the NobelPrize.org, Banting approached Professor John Macleod at the University of Toronto, on a possible way of treating diabetes. He proposed to ligate the pancreative ducts to stop the flow of nourishment to the pancreas.

This in turn would cause the pancreas to degenerate and stop it from secreting digestive juices, enabling the extraction of an anti-diabetic secretion from the pancreas.

Although he did not really think much of his theory, Macleod gave him a laboratory with minimum equipment and 10 dogs and an assistant, medical student Charles Best. When the tests proved successful, the experiment was expanded and the extract was named 'insulin'.

During the testing process, the team discovered that there was no need to shrink the pancreas and that they could use whole fresh pancreas from adult animals.

Google doodle
Google doodle celebrates Sir Frederick Banting's 125th birthday Google doodle

In late 1921, biochemist Bertram Collip joined the team, to try and purify the insulin so that it can be tested on humans. To kick start treatment on humans, Banting and Best became the guinea pigs, testing the purified insulin on themselves.

In January 1922, 14-year-old boy Leonard Thompson became the first person with diabetes to be treated with insulin. Leonard, who was near death, rapidly regained strength and appetite after the treatment. The test was a success.

There was, however, some controversy when the Noble Committee decided in 1923 to award Banting and Macleod the Nobel Prize in Physiology or Medicine. Banting was furious as he felt that the award should have been given to him and Best and not Macleod.

Despite this, Banting shared his cash award with Best, while Macleod shared his award with Collip.

The team patented the insulin extract but gave away all their rights to the University of Toronto which used the income from insulin to fund new research.

Banting was born on 14 November 1891 in Alliston, Canada. He went to the University of Toronto to study divinity but later switched to medicine and received his degree in 1916. He served the Canadian Army Medical Corps and served in France during the First World War.

In 1918, he was wounded at the battle of Cambrai and the following year was awarded the Military Cross for heroism under fire. After the war, he returned to Canada where he studied orthopaedic medicine.