Molecular Pathology- Miscellaneous I
Question No. 16. The Answer is: (B) Secondary structure of amplicons.
Discussion: Single stands of DNA with slightly differing sequences will adopt slightly different secondary structures and will migrate through a gel at slightly different rates.. This is one way to screen PCR fragements for possible mutations. The migration pattern produced by an unknown patient sample is compared against a wildtype (or mutated) sample to see if a mutation exists in the patient sample. Generally, samples showing different patterns of migration from the controls are subsequently sequenced. Application of a current in multiple orientations is used in pulse field electrophoresis that is used in separation of very large molecules