Rediscover STEAM
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Rediscover STEAM

Martha Chase, Geneticist

Born on November 30th, 1927 in Cleveland, Ohio, Martha Chase pioneered our knowledge of the field of genetics. Her work laid the foundations for gene therapy and modern technologies like CRISPR today.

In 1950, Chase earned her Bachelor’s degree from the College of Wooster, and in 1964, she received her Doctoral Degree in Microbiology from the University of Southern California. After completing her studies, she worked as a research assistant for Alfred Hershey at the Carnegie Institution of Washington, where the two eventually conducted the notable series of experiments, known as the Hershey-Chase experiments, that verified that genes were made up of deoxyribonucleic acid (DNA).

Martha Chase and Alfred Hershey

The Hershey-Chase experiments cleared up the common misconception that scientists in the 1940s held that the genetic material was a protein. At first, most geneticists were skeptical, but the results of Alfred Hershey and Martha Chase’s work published in 1952 changed their minds.

Chase and Hershey performed their experiments on the viruses that infect bacteria, known as bacteriophages. These experiments showed that bacteriophages may “act like tiny syringes” containing genetic material. To test this theory, the two geneticists utilized radioactive sulfur to label bacteriophage proteins and radioactive phosphate to label their DNA. Next, they allowed the viruses to attack the bacterial cells. The bacterial cultures were placed in a blender then centrifuge to separate the bacteria from smaller particles. Through this test, Hershey and Chase found that most of the bacteriophage DNA remained with the bacterial cells while their protein was released. They concluded that the protein and DNA both played separate roles in terms of the bacterial cells. “The protein played a role in adsorption to the bacteria and helped inject the viral DNA into the bacterial cell.” Thus, it was the DNA that was involved in the growth and multiplication of bacteriophage within the infected bacterial cell, and so Chase and Hershey proved that DNA was the genetic material, not protein.

Summary of Hershey-Chase Experiment

In 1969, only Alfred Hershey was awarded a Nobel Prize for their discovery. Despite the vital role that she played in the Hershey-Chase experiments, Chase did not receive a Nobel Prize or really any recognition as she was a female. Overall, Martha Chase is an inspiration to all women who aspire to pursue genetics or microbiology. She made incredible discoveries that continue to shape medicine today despite facing great societal obstacles as a woman in science.

by Tanisha Shah


23andMe. “Women Who Advanced Genetic Science.” 23andMe Blog, 24 Mar. 2020,

“World of Microbiology and Immunology.” 14 Jul. 2020 .”,, 23 July 2020,

Hernandez, Victoria. “The Embryo Project Encyclopedia.” The Hershey-Chase Experiments (1952), by Alfred Hershey and Martha Chase | The Embryo Project Encyclopedia, 23 June 2019,

“Hershey and Chase.” BioNinja,



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