Martha Chase
- In full:
- Martha Cowles Chase
- Also called:
- Martha C. Epstein
What was Martha Chase’s role in the Hershey-Chase experiment?
What was Martha Chase’s educational background?
What research did Martha Chase conduct with geneticist August Doermann?
How has Martha Chase been recognized in recent years?
Martha Chase (born November 30, 1927, Cleveland, Ohio, U.S.—died August 8, 2003, Lorain, Ohio) was an American molecular geneticist who played a pivotal role in the Hershey-Chase experiment of 1952, which provided strong evidence that DNA is the genetic material of living organisms.
Education and early career
Chase grew up in Cleveland Heights, Ohio, and attended the College of Wooster in Wooster, Ohio, where in 1950 she graduated with a bachelor’s degree in biology. She subsequently worked as a research assistant to American biologist Alfred Hershey at the Carnegie Institution of Washington’s Cold Spring Harbor Laboratory on Long Island, New York. It was there, starting in 1951, that Chase and Hershey performed breakthrough studies on bacteriophages, which are viruses that infect bacteria by inserting their genetic material into a bacterial cell and then replicating within the cell. The two researchers carried out experiments to validate the findings of previous work showing that the DNA and protein components of bacteriophages are separable. They also sought to determine whether the genetic material from infectious phages consisted of DNA or protein.
In the final experiment conducted by Hershey and Chase, which came to be known as the Hershey-Chase experiment, they labeled phages with radioactive phosphorus (for DNA) and radioactive sulfur (for protein) and then infected separate E. coli samples with the radiolabeled phages. After mixing the samples in a Waring blender—used instead of a centrifuge to avoid damaging the bacterial cells—they found that only the radioactive phosphorus had entered the bacteria. In this way they demonstrated that only DNA had entered the cells, thereby confirming that DNA is the replicating genetic material, rather than protein, as previously thought.
Later career
In 1953 Chase left Cold Spring Harbor Laboratory, having accepted a position with American geneticist August Doermann at Oak Ridge National Laboratory in Tennessee. There she worked with Doermann to study the genetic properties of bacteriophages in preparation for his move to the University of Rochester that fall. Chase went with Doermann to Rochester, where they conducted pivotal research in the field of phage genetics. Their work, particularly experiments to induce mutations in phage DNA using ultraviolet radiation, laid the groundwork for understanding phage recombination and gene transfer. In a study of gene mapping, they found that genes are arranged in a defined linear sequence.
Between 1953 and 1959 Chase returned to Cold Spring Harbor each summer for annual meetings of the Phage Group, an informal network of scientists. In 1959 she moved to California to pursue doctoral studies in microbiology at the University of Southern California. While there she married phage virologist Richard Epstein; the couple divorced soon after. Chase received a Ph.D. in 1964. Several years later, having been unable to secure a faculty position, her scientific career ended. She returned to Cleveland to live with her family and later was affected by dementia.
Recognition
Although Chase was listed as co-author of the 1952 paper that presented the Hershey-Chase experiment, her role in the research went unrecognized. Indeed, in 1969 Hershey won the Nobel Prize in Physiology or Medicine, alongside Italian-born American biologist Salvador Luria and German-born American biologist Max Delbrück. The three men were honored “for their discoveries concerning the replication mechanism and the genetic structure of viruses.” During his Nobel lecture Hershey did not acknowledge Chase’s contributions.
In recent decades Chase’s involvement in research on the genetic properties of bacteriophages has been more openly acknowledged in scientific histories. In 2021 a family of bacterial viruses, Chaseviridae, was named in her honor.
