The DNA Step Ladders are ladders of defined sizes with exact incremental steps between bands. The ladders are not intended for use in quantitative analysis. Each ladder is provided with a tube of 6X Blue/Orange Loading Dye. The fragments may be stained with ethidium bromide.
25bp DNA Step Ladder: Twelve DNA fragments ranging from 25bp to 300bp in 25bp increments. An 1,800bp "backbone" fragment is also visible. The 300bp band is ≈3 times more intense than all other bands.