A number of proprietary plasmids aredigested to completion with appropriate restriction enzymes to yield 10 bandssuitable for use as molecular weight standards for agarose gel electrophoresis.The digested DNA includes fragments ranging from 0.5-10.0 kilobases(kb). The 3.0 kb fragment has increased intensity to serve as a reference band.The approximate mass of DNA in each of the bands is provided (assuming a 0.5 μgload) for approximating the mass of DNA in comparably intense samples ofsimilar size.