No. 3014: MEASURING ALMOST NOTHING

by Richard Willson

Click here for audio of Episode 3014

Today, we measure almost nothing. The University of Houston’s college of engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

What happens when we vaccinate someone against a virus? The vaccine is a weakened form of the virus. It stimulates the immune system to make anti-bodies that bind to the virus. We can produce antibodies that bind to almost any given substance.

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A 3D model of an Immunoglobulin molecule, showing heavy chains in blue and light chains in green. Photo Credit: Wikimedia Commons

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Antibody structure schematic. An antibody is made up of two heavy chains and two light chains. The variable region, which differs from one antibody to the next, allows an antibody to recognize its matching antigen. Photo Credit: Wikimedia Commons

A tool that can bind tightly to a substance like a virus ought to be useful in detecting that substance at very low levels, but how? Enter Roslyn Yalow, who got the Nobel Prize for solving this problem. She made antibodies useful in medical diagnosis by labeling them with highly-detectable radioactive isotopes.

Yalow was born in New York and was fascinated by physics. But her parents had not graduated from college, and physics was then almost entirely dominated by men. As she put it: “I was excited about … a career in physics. My family, being more practical, thought the most desirable position for me would be as an elementary school teacher.”

Yalow graduated with high honors at age 19 as the first physics major at Hunter College. Then she had trouble being admitted to Ph.D. studies. One Midwestern school actually wrote back to her professor: “She is from New York. She is Jewish. She is a woman.” She later got an A-minus in one graduate laboratory course, and the department chair said this proved that women could not excel at lab work.

She did excel, and she did it in nuclear physics. She learned the sensitive measurement of radioactive substances. Later she worked with Solomon Berson at the VA Hospital in the Bronx. They proved that even small proteins like the diabetes hormone insulin could be recognized by antibodies. Nobody believed them at first. Equally important, their methods of following antibody binding using radioactive labels made it possible to detect tiny quantities of almost anything.

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Dr. Rosalyn Yalow at her Bronx Veterans Administration Hospital, October 13, 1977, after learning she was one of three American doctors awarded the Nobel Prize for Physiology or Medicine that year Photo Credit: Wikimedia Commons

Yalow refused to patent what she called her “radio-immuno-assay”. As she put it: “We never thought of patenting … . Patents are about keeping things away from people for the purpose of making money. We wanted others to be able to use it”.

Yalow’s radio-immuno-assay used radioactive isotopes to label antibodies, which limited its use. Now immunoassay also can use safer labels like enzymes and gold nanoparticles. It’s a fundamental tool in biology and medicine. It’s used to test blood for hepatitis and AIDS infections, and to detect contaminants in food and water. In the home pregnancy test, antibodies to pregnancy hormones are labeled with tiny particles that form the line on the strip.

Later in life, Yalow spoke to a group of children about life in science. “Initially, new ideas are rejected,” she told them. “Later, if you’re right they become dogma. And if you’re really lucky you can publish your rejection letters as part of your Nobel Prize presentation.”

I’m Richard Willson at the University of Houston, where we’re interested in the way inventive minds work.

(Theme music)

Yalow Obituary in the NY Times http://www.nytimes.com/2011/06/02/us/02yalow.html?pagewanted=all&_r=2&

Modern Drug Discovery biography: http://pubs.acs.org/subscribe/archive/mdd/v04/i09/html/09timeline.html

Straus, E. Rosalyn Yalow, Nobel Laureate: Her Life and Work in Medicine; Basic Books, 1998.

Contributions of 20th Century Women to Physics: http://www.physics.ucla.edu/~cwp/Phase2/Yalow,_Rosalyn_Sussman@861234567.html

Nobel autobiography: www.nobel.se/medicine/laureates/1977/yalow-autobio.html;

And lecture: http://www.nobelprize.org/nobel_prizes/medicine/laureates/1977/yalow-lecture.html

This episode was first aired on July 28, 2015