Wallace Henry Coulter (1913–1998)

Wallace Henry Coulter was an engineer, inventor, and entrepreneur who was co-founder and chairman of Coulter Corporation, a worldwide medical diagnostics company headquartered in Miami, Florida. The two great passions of his life were applying engineering principles to scientific research and embracing the diversity of world cultures.

Wallace Coulter was born on February 17, 1913, in Little Rock (Pulaski County) to Joseph R. Coulter and Minnie May Johnson Coulter. His father was a train dispatcher, and his mother was an elementary school teacher; he had one brother. Coulter spent his youth in McGehee (Desha County), graduating from McGehee High School. He attended his first year of college at Westminster College in Fulton, Missouri; his interest in electronics, however, led him to transfer to the Georgia Institute of Technology for his second and third years of study. Due to the Great Depression, he was unable to complete his education.

In 1937, he joined General Electric (GE) as a sales and service engineer in the Chicago, Illinois, area. This work familiarized Coulter with the testing procedures in a hospital laboratory. When an opportunity to cover eastern Asia presented itself in 1939, he seized the chance to live and work abroad. During the next twenty-four months, he was based in three areas covering the entire Far East: Manila, the Philippines; Shanghai, China; and Singapore. Coulter left Singapore on February 9, 1942, as the Japanese were bombing the city. It took him nearly a year to return to the United States via India, Africa, and South America. On arriving in New York, Wallace joined Press Wireless, Inc., and continued to work there into 1945.

After World War II, Coulter worked for several electronics companies, including Raytheon Manufacturing Company and Mittleman Electronics in Chicago. He maintained a laboratory at home to work on promising ideas and projects. Using blood, a needle, and some cellophane, Wallace demonstrated his invention of the Coulter principle, a means for counting and sizing microscopic particles suspended in a fluid.

Remembering his visits to hospitals, where he observed lab workers hunched over microscopes manually counting blood cells smeared on glass, Coulter focused the first application of his principle on counting red blood cells, developing an instrument that became known as the Coulter Counter. This simple device increased the sample size of the blood test 100 times than the usual microscope method by counting as many as 6,000 cells per second. The Coulter Principle is responsible for the current practice of hematology laboratory medicine.

Coulter’s patent was issued on October 20, 1953. Two prototypes were subsequently sent to the National Institutes of Health (NIH) for evaluation. Shortly after, the NIH published its findings in two key papers, citing improved accuracy and convenience of the Coulter method of counting blood cells. That same year, Coulter publicly disclosed his invention at the National Electronics Conference in his one and only technical paper, “High Speed Automatic Blood Cell Counter and Cell Size Analyzer.” In 1958, he and his brother, Joseph, founded Coulter Electronics, Inc., to manufacture, market, and distribute their Coulter Counters.

The use of the Coulter Principle modernized industry by establishing a method for quality control and standardization of particles used in a variety of products. The impact of the Coulter Principle to the medical, pharmaceutical, biotechnology, food, beverage, and consumer industries is immeasurable. Overall, Coulter received eighty-five patents (three issued posthumously), many of which were issued to him for discoveries made late in his life. His many patents included further developments of the original Coulter Counter.

In 1960, he was awarded the highly prestigious John Scott Award for Scientific Achievement, given to inventors whose innovations have had a revolutionary effect on mankind. He continued to receive many other awards from business, industry, and academia, including honorary doctorates from Westminster College, Clarkson University, the University of Miami, Barry University, and the Georgia Institute of Technology. Although he was not a physician or hematologist, Coulter was the only person to receive the American Society of Hematology Distinguished Service Award for his enormous contribution to the field of hematology. In 1998, he was inducted into the National Academy of Engineering. In 2004, Coulter was posthumously inducted into the National Inventors Hall of Fame.

Coulter never married or had children. He died on August 7, 1998, and is buried in Woodland Cemetery in Miami.

For additional information:
Graham, Marshall. “The Coulter Principle: For the Good of Humankind.” Master’s thesis, University of Kentucky, 2020. Online at https://uknowledge.uky.edu/history_etds/62/ (accessed April 4, 2022).

Graham, Marshall Don. “The Coulter Principle: The Arkansas Background.” Arkansas Historical Quarterly 73 (Summer 2014): 164–191.

Saxon, Wolfgang.“Wallace Coulter, 85, Inventor of Medical Diagnostic Tools.” New York Times obituary, August 17, 1998, p. A13. Online at http://www.nytimes.com/1998/08/17/us/wallace-coulter-85-inventor-of-medical-diagnostic-tools.html (accessed April 4, 2022).

Sfat, Michael R. Memorial Tributes: National Academy of Engineering 9 (2001): 54–57.

Wallace H. Coulter Foundation. http://www.whcf.org (accessed April 4, 2022).

Mara Neal
Wallace H. Coulter Foundation


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