Nucleic acid is isolated from rotavirus if the GC content is

Nucleic acid is isolated from rotavirus if the GC content is 40%
what would you expect the AU content to be?

Solution

Chargaffs rule says that purines and pyrimidines have been in 1:1 raio within DNA. Total amount of purines = Total amount of pyrimidines A+G =T+C A:T =1 ; G:C = 1 According to this rule G=C and A=T GC = 40% G= 20% and C =20% then AT = 100 - 40 = 60% Out of 60%, 60/2 = 30 A= 30% and T =30% But the AU content could be seen in double stranded RNA viruses such as rotavirus Here instead of T, observed is U So, U = 30% and A = 30% Then AU = 60%