Which of the following DNA oligonucleotides has higher melti

Which of the following DNA oligonucleotides has higher melting temperature?

A) A-T-G-C-G-A-T-G-C T-A-C-G-C-T-A-C-G

B) C-T-A-C-T-A-A-G-A G-A-T-G-A-T-T-C-T

C) T-A-C-G-C-T-A-T-A A-T-G-C-G-A-T-A-T

D) G-A-T-A-A-T-T-C-G C-T-A-T-T-A-A-G-C

The answer is A, can someone explain why?

Solution

Answer A is correct because there is more Guanine Cytosine pairs which has three hydrogen bonds as compared to thymine adenine pairing which has two hydrogen bonds. Higher the GC content higher will be the melting point.