US EPA

474036 

Journal Article 

The early history of P-32 as a radioactive tracer in biochemical research - A personal memoir 

Gest, H 

2005 

33 

3 

159-164 

English 

The concept of using radioactive isotopes as "tracers" of chemical conversions was conceived and developed by inorganic chemist Georg de Hevesy ( Nobel Laureate in Chemistry 1943). In 1935, he began to apply the technique to various biological processes using P-32, and his experiments revealed the dynamic character of physiology and metabolism. Following de Hevesy's lead, Samuel Ruben ( University of California, Berkeley) exploited P-32 in 1937-38 for investigation of phospholipid metabolism. Between 1937 and 1940, Ruben and colleague Martin Kamen spearheaded tracer studies in various biological systems using P-32, short-lived C-11, and other radioactive isotopes. During this period, Kamen was responsible for cyclotron-produced radioactive tracers and was able to sustain de Hevesy's research by supplying him with P-32. In 1940, Ruben and Kamen discovered long-lived C-14, which later proved to be a very powerful tool for analysis of complex biochemical processes, such as the path of carbon in photosynthesis. Between 1946 and 1950, P-32 was used in studies of bacteriophage replication and photosynthetic metabolism. This memoir surveys the history of these early investigations. 

phosphorus-metabolism; photosynthesis; discovery; microorganisms; chemistry