The origins of clinical chemistry

When Fred Banting showed up in Toronto to begin his experiments with Professor Macleod, he had no formal training in laboratory experiments.  Macleod had years of experience in planning and executing experiments.  He saw the many holes in Banting’s plan and tried to provide what he knew Fred would need.

Macleod assigned Banting an assistant, Charles Best.  Best was ambitious and talented, but not very experienced.  He had just finished a bachelor’s degree at the University of Toronto and was pursuing a Master’s degree working under the Macleod’s supervision.  Best’s initial responsibility would be to help with the surgical procedures and measure the glucose blood levels.

Banting needed a method to test whether insulin was improving the dog’s health.  The most straightforward method was to measure the blood glucose levels at regular intervals (15 minutes, for instance).  If the blood glucose levels decreased, the insulin was working.

The measurement of glucose, a specific form of sugar, in blood was not easy at the time.  A paper from 1915, (Lewis and Benedict JBC) describes the need for a method of measuring blood sugar that is “quick, accurate, and adapted for use with small blood samples,” then goes on to propose a new method that “we believe meets all these qualifications”.

These desirable characteristics have been repeated in papers many times over the past century.  Every decade the tests get quicker, more accurate and require less blood.  In later years, a new requirement appears, ease of use.  This requirement allows the patient to measure their own blood sugar levels, rather than relying on a trained laboratory technician.