Erwin Chargaff's work on the composition of nucleic acids began in 1944. His findings, which later became known as Chargaff's rules, detail the specific pairings that occur in double-stranded DNA molecules.
According to one of Chargaff's rules, a section of DNA molecules that contains 50 base pairs and has 15 adenine bases must also contain --
According to Chargaff's rules, in double-stranded DNA, the amount of adenine (A) is equal to the amount of thymine (T), and the amount of guanine (G) is equal to the amount of cytosine (C). Therefore, if a section of DNA molecules has 15 adenine bases, it must also have 15 thymine bases. Additionally, the number of guanine bases and cytosine bases would be equal to each other and to the number of adenine bases, so it would also have 15 guanine bases and 15 cytosine bases. However, since DNA contains thymine instead of uracil, it would not contain any uracil bases.
