His early work included stories of the complexlipids, the fats or fatty acids that occur in microorganisms. Helping discoverthe unusual fatty acids and waxes in acid-fast mycobacteria led him to study themetabolism and biological role of lipids in the body. Chargaff was also apioneer in the use of radioactive isotopes of phosphorus as a tool to study inthe synthesis and breakdown of phosphorus-containing lipid molecules in livingcells. He published a paper on the synthesis of a radioactive organic compoundcalled alpha-glycerophosphoric acid. He began to study nucleic acids in 1944,while at Colombia.
Until this time scientists believed that amino acids carriedgenetic information. DNA was also believed to contain the tetranucleotides madeup of cytosine, thymine, adenine and guanine, that served as an attachment sitefor the amino acids that made up genes. It was already known that a cell’snucleus is comprised in part by DNA, Chargaff was able to determine how much ofwhich bases were present by measuring the amount of light each quantity of baseabsorbed. He showed that adenine and thymine occur in DNA in equal proportionsin all organisms and that cytosine and guanine are also found in equalquantities. Chargaff’s major conclusion is that DNA carries genetic information,and the number of different combinations in which the four nucleic acids appearin DNA provides enough complexity to form the basis of heredity.
Finally, heconcluded that the identity of combinations differs from species to species andthat DNA strands differ from species. Overall, his findings were importantcontributions in biochemistry, including the addition of a key piece in thepuzzle of the structure of DNA. This all led to major developments in the fieldof medical genetics, and, ultimately helped pave the way for gene therapy andthe birth of the biotechnology industry.