Maclyn McCarty

Maclyn McCarty (June 9, 1911 – January 2, 2005) was an American geneticist. He was the last surviving member of a scientific team in Manhattan that made an important discovery in the 1940s. This team showed for the first time that genes were made of DNA, not protein, which people used to believe before.

McCarty worked at Rockefeller University for over 60 years. His most famous work was part of the Avery–MacLeod–McCarty experiment. In this experiment, he and his team studied bacteria. They learned that DNA was the substance that carried genetic information in these bacteria. This discovery helped scientists understand how traits are passed from parents to children.

In 1994, the world celebrated the 50th anniversary of this important discovery. McCarty’s work changed how we study life and heredity. He spent his career studying diseases caused by tiny organisms.

Early life

Maclyn McCarty was born in South Bend, Indiana. He grew up with three brothers. His father worked for the Studebaker Corporation.

He studied biochemistry at Stanford University. There, he worked with James Murray Luck. He finished his studies in 1933. He then got his medical degree at Johns Hopkins University in 1937. After spending more time at New York University, he joined Rockefeller University. This is where he met the people he would later work with on his research.

Early Rockefeller years

When Maclyn McCarty joined Rockefeller University, he worked with a team that had already made important discoveries. Over the next few years, they kept working on their research. In 1944, they shared what they found in the Journal of Experimental Medicine. They showed that DNA was linked to life processes.

At first, many scientists were not sure about the idea that genes were made of DNA. It took time for others to agree with this discovery. It wasn’t until 1953, after Watson and Crick's bihelical structure of DNA was shown, that most researchers agreed with their work from 1944.

Later career years

After retiring in 1946, McCarty led a special laboratory with scientist Rebecca Lancefield. They found that infections could affect the joints and heart later on. McCarty studied these infections by looking at patients and their samples.

McCarty and his team made big steps in learning about bacteria, especially a type called group A streptococci. They studied the bacteria's structure and found important parts like polysaccharide and peptidoglycan. They also created tests to find immune responses to these bacteria, which helped diagnose diseases such as rheumatic fever. McCarty’s work improved medical practices, including using C-reactive protein levels to find inflammation.

In his later years, McCarty became a leader in biomedical science. He held important jobs at Rockefeller University and gave advice to many groups, including the Helen Hay Whitney Foundation, the Institute of Medicine, and the Journal of Experimental Medicine. He was also part of famous groups such as the United States National Academy of Sciences, the American Academy of Arts and Sciences, and the American Philosophical Society.

Personal life

Maclyn McCarty had many close friends around the world. He was warm and funny, and he loved English books, plays, and music. He liked to visit cities such as Paris, New York, and London, especially after he retired. McCarty was also very close to his family. He and his four brothers met every year for family gatherings.