Helen M. Free

Helen M. Free

1913 – 2021

Developed convenient diagnostic test techniques

Enshrined:  1996

Major Field of Study: Chemistry

Specific Accomplishment: Helen Murray Free was the wife in the husband-and-wife team of biochemists who revolutionized diagnostic urine testing with their invention of an easy-to-use, chemically coated paper dipstick that measures a patient’s blood sugar by changing color when dipped in a urine sample.  Her research work in diagnostic chemistry led to the development of the first easy-to-perform quantitative detection of glucose in urine for diabetes patients; and later, with her husband, Alfred Free, she co-developed diagnostic test strips (ubiquitous “dip-and-read” tests) for glucose and other parameters in urine.

High School: Graduated in 1941 as the valedictorian of Poland Seminary High School in a Youngstown, Ohio suburb

Bachelor’s Degree:  B.S. in Chemistry from College of Wooster (Ohio) in 1944

Master’s Degree:  M.A. in Management from Central Michigan University in 1978

Doctor’s Degree:  Honorary Doctorate of Science from both Wooster and Central Michigan University

Engineering and Science Achievements:

Her husband, Alfred Free, came up with the idea of a dipstick, or urine test strip—a strip of paper coated with a chemical that turns color in the presence of a particular chemical substance in urine. Together Helen and Alfred Free developed Clinistix®, the first “dip-and-read” test for glucose in urine. Helen and Alfred went beyond testing for glucose and developed other strips for testing levels of key indicators of disease. Once they achieved success with a number of different test strips, they turned their attention to combining more than one test on a single strip. By 1981 they had developed Multistix®, a strip for urinalysis that had 10 different clinical tests on a single strip. Their inventions revolutionized diagnostic urine testing.

Additional Details:

Helen Murray was born on February 20, 1923 in Pittsburgh, Pennsylvania.

She received her early education from the public schools in Youngstown, Ohio, and graduated in 1941 as the valedictorian of Poland Seminary High School. While attending a summer church camp at the College of Wooster, Helen set her heart on attending Wooster, and arrived on the Wooster campus in September 1941. Greatly influenced by her high school English teacher, she originally intended to major in English and Latin in hopes of becoming a teacher; however, these plans soon changed. 

In December 1941, Pearl Harbor was bombed, causing many of Wooster’s male students to either enlist or be drafted into the army to fight in World War II. Six months later, the housemother at Helen’s dorm advised some of her young charges to go into science, a predominantly male discipline, to fill the void. Given this advice, Helen, who liked her chemistry course and was getting good grades, switched majors to chemistry.

She has said that her switch to chemistry was the “most terrific thing” that ever happened to her. 


After graduating from Wooster, Helen immediately began working as a quality control chemist for Miles Laboratories (known as the creators of Alka-Seltzer); however, she aspired to be a researcher as opposed to working in quality control. When Alfred Free had a position open in his biochemistry research group, she interviewed and filled the position.  They would marry in 1947 and have six children. 

One of the early developments of the Free research group was a tablet for testing the level of glucose in the urine of diabetes patients. Miles Laboratories had already developed such a tablet, but the Frees and their colleagues were asked to make it more sensitive. The improved tablet contained cupric sulfate, citric acid, and sodium hydroxide. When the tablet was placed in a small test tube with a diluted urine solution, it gave a quantitative result by causing color changes from green (0.5% glucose) to orange (2% glucose).  It was the first diagnostic test of its kind: it could be done in a doctor’s office or a hospital without elaborate laboratory facilities. Much later it was realized that the test was simple enough to allow patients to do their own monitoring at home. The group also developed additional tests for diabetics and, in keeping with the pattern of turning clinical tests into tablets, the Frees also developed a product for diagnosing hepatitis A. It worked by chemically detecting the presence of a substance called bilirubin in urine, a symptom of the disease. 

Later, Free worked with her husband to move the tests from tablets to strips, introducing the Clinistix® “dip-and-read” test in 1956. It was the first dip-and-read diagnostic test strip for monitoring glucose in urine. By 1981 they had developed Multistix®, a strip for urinalysis that had 10 different clinical tests on a single strip. 

In 1969, Free moved into the Growth and Development Department at Miles, and she eventually became the director of Specialty Test Systems in 1976. She was Director of Marketing Services for the Research Products Division when Bayer Diagnostics acquired Miles in 1978. 

From 1979 to 1982, she was an Adjunct Professor of Management at Indiana University South Bend. 

Patents and Publications:

Free earned seven patents for her improvements in medical and clinical urinalysis testing including U.S. Patent 2,912,309, “INDICATOR FOR DETECTING GLUCOSE” and, with her husband, U.S. Patent 3,087,794,   “CHEMICAL TEST FOR DIFFERENTIATING LEUCOCYTES FROM ERYTHROCYTES.” 

She and her husband co-authored two books including Urinalysis in Laboratory Practice, which is still a standard work in the field. 

Awards and Honors received by Helen Murray Free:

Both Helen Free and her husband, Alfred Free, were inducted into the Engineering and Science Hall of Fame in 1996 and the National Inventors Hall of Fame in 2000.  In 2010, she received the National Medal of Technology and Innovation, the highest honor bestowed by the United States government on scientists, engineers, and inventors.

In 1980, Garvan–Olin Medal, given to women for distinguished service in the field of chemistry. 

In 1996, Kilby Award for lifetime achievement.

In 2000, inducted into the National Inventor’s Hall of Fame.

In 2006, Award for Outstanding Contributions to Clinical Chemistry.

In 2010, awarded the National Medal of Technology and Innovation by President Barack Obama.

The American Chemical Society named an award in her honor: the Helen M. Free Award in Public Outreach.

The work of Helen and Al Free in developing diagnostic test trips was designated a National Historic Chemical Landmark by the American Chemical Society on May 1, 2010, at the ETHOS Science Center in Elkhart, Indiana. 


Helen Murray Free, interview by James J. Bohning in Elkhart, Indiana, 14 December 1998 (Philadelphia: Chemical Heritage Foundation, Oral History Transcript #0176)




Helen Free. Wikipedia.