The Low Range ssRNA Ladder is a set of 6 RNA molecules produced by in vitro transcription of a mixture of 6 linear DNA templates. The ladder sizes are: 1000, 500, 300, 150, 80 and 50 bases. The 300 base fragment is at double intensity to serve as a reference band. This ladder is suitable for use as an ssRNA size standard on denaturing polyacrylamide-urea gels, and on denaturing or native agarose gels.