Heteroduplex analysis
Heteroduplex analysis (HDA) is a method in biochemistry used to detect point mutations in DNA (Deoxyribonucleic acid) since 1992.[1] Heteroduplexes are dsDNA molecules that have one or more mismatched pairs, on the other hand homoduplexes are dsDNA which are perfectly paired.[1][2] This method of analysis depend up on the fact that heteroduplexes shows reduced mobility relative to the homoduplex DNA.[3] heteroduplexes are formed between different DNA alleles.[4] In a mixture of wild-type and mutant amplified DNA, heteroduplexes are formed in mutant alleles and homoduplexes are formed in wild-type alleles.[5] There are two types of heteroduplexes based on type and extent of mutation in the DNA. Small deletions or insertion create bulge-type heteroduplexes which is stable and is verified by electron microscope.[6] Single base substitutions creates more unstable heteroduplexes called bubble-type heteroduplexes, because of low stability it is difficult to visualize in electron microscopy.[5] HDA is widely used for rapid screening of mutation of the 3 bp p.F508del deletion in the CFTR gene.[6]