DNA Step Ladders have defined sizes with exact incremental steps between bands. The ladders are not intended for use in quantitative analysis. The DNA fragments may be stained with ethidium bromide.
The 25bp DNA Step Ladder has 12 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.
Storage Buffer: 10mM Tris-HCl (pH 7.4), 1mM EDTA.