Rapid preparation of single stranded DNA from PCR products by streptavidin induced electrophoretic mobility shift.

Streptavidin induced electrophoretic mobility shift was used to prepare single stranded (ss) DNA amplified with the polymerase chain reaction in the presence of a biotinylated and a non-biotinylated primer. A variety of denaturing conditions, including incubation at 95 degrees C in 50% formamide can be used without disrupting the streptavidin-biotinylated-ssDNA complex. Following electrophoresis, pure non-biotinylated DNA can be efficiently recovered from 7 M urea gels because it is well separated from the severely retarded streptavidin-biotinylated-ssDNA complex. Quantitative complexing of biotinylated ssDNA can occur at a streptavidin to DNA molar ratio of 1 or more.