A unique combination of PCR products and a number of proprietary plasmids digested with appropriate restriction enzymes to yield 12 fragments, suitable for use as molecular weight standards for agarose gel electrophoresis. The DNA includes fragments ranging from 100-3,000 base pairs. The 500 and 1,500 base pair bands have increased the intensity to serve as reference points. The approximate mass of DNA in each band is provided (0.54 μg a load) for approximating the mass of DNA in comparably intense samples of similar size.

Source
PCR products and double-stranded DNA digested with appropriate restriction enzymes are phenol extracted and equilibrated to 10 mM Tris-HCl (pH 8.0) and 10 mM EDTA.