Helen Murray Free Dies at 98; Chemist Developed Diabetes Test – The New York Times
Helen Murray Free, a chemist who ushered in a revolution in diagnostic testing when she co-developed the dip-and-read diabetes test, a paper strip that detected glucose in urine, died on Saturday at a hospice facility in Elkhart, Ind. She was 98.
Before the invention of the dip-and-read test in 1956, technicians added chemicals to urine and then heated the mixture over a Bunsen burner. The test was inconvenient, and, because it could not distinguish glucose from other sugars, results were not very precise.
They faced two challenges. First, they needed to refine the test so that it would detect only glucose, the form of sugar that is found in the urine of people with diabetes. Second, the chemicals they needed to use were inherently unstable, so they had to find a way to keep them from reacting to light, temperature and air.
The first problem was easily solved with the use of a recently developed enzyme that reacted only to glucose. To stabilize the chemicals, the Frees experimented with rubber cement, potato starch, varnish, plaster of Paris and egg albumin before settling on gelatin, which appeared to work best.
With her husband, Ms. Free wrote two books on urinalysis. Later in her career she returned to school, earning a master’s in clinical laboratory management from Central Michigan University in 1978 at age 55. She held several patents and published more than 200 scientific papers.
At Miles, she rose to director of clinical laboratory reagents and later to director of marketing services in the research division before retiring in 1982; by then the company had been acquired by Bayer. She was elected president of the American Chemical Society in 1993. In 2009, she was awarded a National Medal of Technology and Innovation by President Barack Obama, and in 2011 she was inducted into the National Women’s Hall of Fame in Seneca Falls, N.Y., for her role in developing the dip-and-read test.
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