KPL GeneRuler yields 21 distinct fragments from 100 bp to 10 kb. The bright bands at 3000 bp, 1031 bp, and 500 bp serve as references. The KPL GeneRuler Biotinylated DNA Ladder is a convenient prelabeled molecular weight marker ideal for use on southern blots. The ladder contains a mixture of labeled and unlabeled DNA which migrate uniformly and will not interfere or cross-hybridize with the target. 21 distinct bands are visible from 100 bp-10 kb. Bright bands at 3000 bp, 1031 bp, and 500 bp serve as reference for easy orientation.