Silver staining of DNA in polyacrylamide gels: Linearity and effect of fragment size

Abstract

Abstract A simplified, inexpensive silver stain for proteins in polyacrylamide gels also stains DNA with a sensitivity of 1 ng (< 0.03 ng/mm 2 ). Sensitivity of detection is superior to ethidium bromide and, for 11 double‐stranded fragments of ϕX174 DNA, staining is linear with respect to concentration. Surprisingly, the slope of staining is similar for pieces of DNA larger than 300 base pairs, but is greater for fragments of smaller size. Staining of DNA with silver is a practical alternative to visualization with ethidium bromide and may serve as a tool for elucidating the basis of silver staining.