AmpFi 50bp Ladder 112 μg / mlPCR products and double stranded DNA were completely digested with appropriate restriction enzymes to generate 17 DNA fragments ranging from 50 bp to 1. 5 kb, which serve as molecular weight standards for agarose gel electrophoresis. The 200 bp and 500 bp bands exhibit increased intensity to provide convenient reference points. The approximate mass of each DNA band (based on a 5 l load of the DNA ladder) is provided to facilitate estimation of DNA