Sigma′s PCR PCR Low Ladder Set contains one vial each of the PCR 100 bp Low Marker and the PCR 20 bp Low Marker. When mixed together, the ladder appears with bands every 20 bp, with every 5th band more intense. About two ul of the mixed ladder should be diluted in gel loading buffer and then loaded in a single lane on an agarose or polyacrylamide gel.
Sigma′s PCR Low Ladder Set is provided as three separate tubes:
1 vial (25 ug) PCR 100 bp Low Marker is provided in a solution of 10 mM Tris-HCl (pH 8.0), with 1.0 mM EDTA.
1 vial (25 ug) PCR 20 bp Low Marker is provided in a solution of 10 mM Tris-HCl (pH 8.0), with 1.0 mM EDTA.
1 vial 6x loading buffer (250 ul volume) containing 15% Ficoll, 0.06% bromophenol blue, 0.06% xylene cyanol FF, and 30 mM EDTA.
1 additional empty tube is provided for storing the mixture.
For optimal resolution, the recommended agarose gel concentration is 2.5%.