Chargaff's rules

Erwin Chargaff was an Austrian biochemist that found out some quantitative relationships in the 1940’s, with his collaborators, that helped to the discovery of the double helix structure of DNA. 

Through research he concluded that the base composition of DNA varies from one species to another and that all tissues of individuals of the same species have the same composition of bases, which allowed him to establish the “Chargaff’s rules”.

The first rule tells us that in every cellular DNA, regardless of the species, the amount of residues of adenine is equal to thymine (A=T) and the amount of guanine residues is equal to that of cytosine (G=C). On the other hand, the second rule says that A+G=C+T, i.e. the sum of the residues of pyrimidines is equal to the sum of the purine residues.

Licenciatura em Biologia Aplicada, 2º ano

Estela Macedo
Luciana Rodrigues
Tânia Pinheiro

Grupo 3