Letter from Joshua Lederberg to Michael Heidelberger

In this exchange between Heidelberger and the molecular geneticist Joshua Lederberg, the two agree on the need to elucidate in detail the chemical composition and three-dimensional structure of pneumococcal polysaccharides. As a molecular geneticist, Lederberg was interested in the structure of pneumococcal polysaccharides because pneumococcus was the organism in which DNA-mediated transformation--the transfer of genetic information carried by DNA--was first observed by Oswald Avery and colleagues. Lederberg believed that detailed knowledge of the structure of pneumococcal polysaccharides would help in understanding the action of the genes that code for them.

NOTE: Dr. Heidelberger's response is written at the bottom of the letter.