The 100bp DNA ladder consists of 12 double stranded DNA fragments ranging from 100bp to 3000bp in increments; 10 fragments from size 100 to 1000bp with an increment of 100bp and two larger fragments with 1500bp and 3000bp. The amounts of 500 and 1500bp fragments are adjusted, so that their increased intensities upon staining serve as easy references after gel electrophoresis. The ladders are supplied pre mixed with loading buffer.