George B. Walden

George B. Walden (February 18, 1895 - August 6, 1982) was a chemist who worked for Eli Lilly and Company on the mass production of insulin. He discovered isoelectric precipitation, which solved a major problem and led to the mass production of insulin.

Insulin was first isolated and successfully tested by Frederick Banting, working in J.R.R. Macleod's laboratory at the University of Toronto in early 1922. A large number of patients suffering from diabetes were on the verge of dying. The supply of insulin was insufficient to treat all the patients. The team at the University of Toronto had inconsistent results in purifying insulin and eventually turned to Eli Lilly for help.

George Walden started working for Eli Lilly in 1917, at which time he was paid $85 each month. George Walden was the head chemist at Eli Lilly in 1922. Previous attempts at purification of insulin attempted to keep the insulin in solution and precipitate out the contaminating proteins. Walden found that if he adjusted the pH to produce the maximum precipitation, the precipitate contained highly purified insulin. His process yielded insulin that was 10 to 100 times more pure then previous batches.