1 kb DNA Ladder is ideal for determining the size of double-stranded DNA from 250 to 10,000 base pairs. The ladder consists of 13 fragments. The 3,000 bp fragment and 1,000 bp fragment are present at increased intensity to allow easy identification. All fragments are blunt-ended. The ladder is available in 2 buffers – no stain (one should add loading dye before electrophoresis) and blue – with bromphenole blue as a tracking dye. Blue buffer contains glycerol, so the ladder is ready for loading on agarose gel.