Free-solution electrophoresis of DNA

We report the first experimental evidence that double-stranded DNA fragments can be electrophoretically separated in free-solution (i.e., in the absence of a sieving matrix) when either a single or two streptavidin molecules are attached to the end(s) using biotinylated nucleotides. As previously predicted, higher resolution is obtained at higher electric fields or when two streptavidin molecules are attached to each DNA fragment, The resolution is also affected by the diameter and coating of the capillaries. (C) 1998 Elsevier Science B.V.