Diamond Ready-to-Use DNA Ladder 250-25kbp is comprised of PCR products and double-stranded DNA that were digested with appropriate restriction enzymes, are phenol extracted, and equilibrated to 10 mM Tris-HCl (pH 8.0) and 10mM EDTA. Diamond Ready-to-Use DNA Ladder 250-25kbp is a unique combination of a number of proprietary plasmids digested with appropriate restriction enzymes and PCR products to yield 14 fragments, suitable for use as molecular weight standards for agarose gel electrophoresis. The DNA includes fragments ranging from 250-25K base pairs. The 1K and 3K bands have increased intensity to serve as reference points. The approximate mass of DNA in each band is provided (0.52 µg a load) for approximating the mass of DNA in comparably intense samples of similar size.