Chargaff found out that the ratios of thymine and adenine were equal and the ratios of guanine and cytosine were equal. He then created the Chargaff's rule states that double stranded DNA has a 1:1 ratio between pyrimidine and purine bases. With this, amount of guanine bases is equal to cytosine bases while the amount of adenine bases is equal to thymine bases.
