bandshiftingThe difference in the rate in DNA band migration on a gel electrophoresis, which occurs despite equal size of a DNA fragment or band.
One way to eliminate bandshifting is with a sequencing gel, in which the actual “signature” of the entire hypervariable—unique to the individual in question—has been previously amplified by a PCR technique. Faster migration is “corrected” by running a “monomorphic” probe which attaches to a fragment of DNA similar in all persons. Bandshifting is a function of the size (number of nucleotides in the band, concentration of the agarose in the gel) and the running time (speed) of the run. The amount of bandshift migration is small (1–4%), but may be significant in forensic DNA analysis.