Predict which of the following DNA oligonucleotide probes would have the highest melting temperature (Tm)when hybridizing to the target sequence 5'-GTGCCTGAATGCAATGTCA-3'.
A)3'-CACGGA-5'
B)3'-CATGGA-5'
C)3'-TTACAG-5'
D)3'-TTACTG-5'

Question

Quizplus · Accepted Answer

DNA with more cytosine and guanine molecules require more heat [energy] to break the three hydrogen bonds formed between these two bases,in contrast to adenine- and thymidine-base pairing,which has only two hydrogen bonds.In addition,single nucleotide mismatches that reduce the complementarity of the hybridization (i.e.no hydrogen bonds formed between noncomplementary bases)will lower the melting temperature.

Predict Which of the Following DNA Oligonucleotide Probes Would Have