Helen Murray Free

Helen Murray Free earned a chemistry degree and then worked at Miles Laboratory for nearly all her career. She and her husband, Alfred Free, invented the paper test strips used for measuring glucose in urine and are recognized more broadly as pioneers in diagnostic chemistry. Their invention relied on creating layers of two enzymes on a paper, with an additional material, such as gelatin, to stabilize the process. The test was conducted by dipping the paper strip into urine and waiting a short time to see the color the paper turned. The test strip process they created has been used to test for the presence of a variety of bodily chemicals in liquids. Helen Murray Free was also a strong advocate of education in the sciences for young people.