The dsRNA Marker consists of ten double-stranded RNAs, 10, 20, 30, 50, 100, 200, 300, 400, 500 and 1,000 base pairs. The dsRNA Marker is an ideal size marker for determinating sizes of double-stranded RNAs. A twenty bp of RNA band including in the dsRNA Marker is adjusted to approximately 25 ng/ul in concentration. The dsRNA Marker is manufactured for non-denaturing polyacrylamide gel electrophoresis. The dsRNA Marker can be visualized by UV light after ethidium bromide staining.