Improved efficiency for primer extension by using a long, highly-labeled primer generated from immobilized single-stranded DNA templates.

Primer extension is one of the most common methods used to measure the amount and size of RNAs. We demonstrate that the sensitivity and the specificity of this method are improved considerably by using a highly-labeled single-stranded DNA generated from a biotinylated single-stranded DNA template, as a long specific primer in the reverse transcription reaction. This new approach allows the detection of transcripts with a low expression level from microgram quantities of total RNA.