Stanley Leibo
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Stanley Leibo
A cryobiologist who helped freeze the first mammalian embryos, then carried the work to cattle, rare species and human eggs.
Stanley Paul Leibo was born on 8 April 1937 in Pawtucket, Rhode Island. He studied at Brown University and the University of Vermont, and took his doctorate in biology at Princeton in 1963. That year he joined Oak Ridge National Laboratory in Tennessee, where he studied what freezing does to living cells.
Two ways to harm a cell. In 1972 Leibo, Peter Mazur and a colleague set out the two-factor hypothesis of freezing injury. A cell cooled too fast can form ice inside itself. A cell cooled too slowly sits too long in salty fluid as the water around it freezes. Good freezing finds the path between the two.
The first frozen mice. The same year, with David Whittingham and Mazur, he showed that slowly cooled mouse embryos could survive minus 196°C. Thawed, they grew into healthy young. Living embryos could be stopped and restarted.
From farms to the wild. From 1981 to 1988 Leibo led research for a cattle embryo transfer business in San Antonio, Texas. There he developed a one-step method that let frozen-thawed cattle embryos be transferred directly, cutting the work from about 90 minutes to 10. He then held posts at Baylor College of Medicine in Houston and the University of Guelph in Canada. At the University of New Orleans he held the Doris Zemurray Stone Chair in Reproductive Biology. He also worked with the Audubon Center for Research of Endangered Species.
Human eggs. Leibo also studied very fast cooling of eggs. In 2005 he was a co-author, with Masashige Kuwayama and Gábor Vajta, of the paper on vitrifying human eggs that Room 6 describes.
He served as president of both the Society for Cryobiology and the International Embryo Transfer Society, which gave him its Pioneer Award in 2009. Leibo died of cancer in Austin, Texas, on 25 March 2014, aged 76.
Also see: Peter Mazur, David Whittingham, Masashige Kuwayama, Gábor Vajta
About the sources
- Embryo Project Encyclopedia (Arizona State University). Stanley Paul Leibo (1937–2014).
- Princeton Alumni Weekly, memorial: Stanley P. Leibo *63.
- International Embryo Transfer Society. Pioneer Award citation, 2009: Stanley Paul Leibo.
- Kuwayama M, Vajta G, Kato O, Leibo SP. Highly efficient vitrification method for cryopreservation of human oocytes. Reproductive BioMedicine Online 2005;11(3):300–308.
- Whittingham DG, Leibo SP, Mazur P. Survival of mouse embryos frozen to -196 degrees and -269 degrees C. Science 1972;178(4059):411–414. PMID 5077328.
- Mazur P, Leibo SP, Chu EH. A two-factor hypothesis of freezing injury: evidence from Chinese hamster tissue-culture cells. Experimental Cell Research 1972;71(2):345–355. PMID 5045639.
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Compiled with AI-assisted research and checked against the original sources. Not yet peer-reviewed. Corrections are warmly welcomed.
