Before the discovery of insulin, diabetes was a feared disease that most certainly led to death.  In 1920, Dr. Frederick Banting, an unknown  surgeon with a bachelor’s degree in medicine took certain idea to Professor John Macleod at the University of Toronto, who was a leading figure in the study of diabetes in Canada. Though Macleod was not much convinced, he gave Banting a laboratory with a minimum of equipment and ten dogs. Banting also got an assistant, a medical student by the name of Charles Best. Banting and Best began their experiments by removing the pancreas from a dog. The dog developed diabetes. Experimenting on another dog, they removed the pancreas, sliced it up, and froze the pieces in a mixture of water and salts. When the pieces were half frozen, they were ground up and filtered. The isolated substance was named “isletin.” The extract was injected into the diabetic dog. Its blood glucose level dropped, and it seemed healthier and stronger. They started using pancreases from cattle. With this new source, they managed to produce enough extract to keep several diabetic dogs alive. They called cattle pancreas extract as “insulin.” In late 1921, biochemist Bertram Collip, joined the team, and was given the task of trying to purify the insulin so that it would be clean enough for testing on humans.

Banting and Best began by injecting themselves with the extract. They felt weak and dizzy, but they were not harmed. Collip continued his work to purify the insulin. He also experimented with trying to find the correct dosage. He learned how to diminish the effect of an insulin overdose with glucose in different forms. He discovered that the glucose should be as pure as possible. In Toronto, Canada, a 14-year-old boy, Leonard Thompson, was chosen as the first person with diabetes to receive insulin. The test was a success. Leonard, who before the insulin shots was near death, rapidly regained his strength and appetite. The team now expanded their testing to other volunteer diabetics, who reacted just as positively as Leonard to the insulin extract. In 1923 the Nobel Committee decided to award Banting and Macleod the Nobel Prize in Physiology or Medicine.

Reference:

http://www.historyorb.com/day/april/15

http://www.nobelprize.org/educational/medicine/insulin/discovery-insulin.html