Determination of the poly(A) tail lengths of a single mRNA species in total hepatic RNA.

Poly(A) tail length is important in the stability and translation of mRNA. We describe procedures for the rapid and reproducible analysis of poly(A) tail length of a single mRNA species contained in a sample of total hepatic RNA. A short 3' fragment of a specific mRNA is prepared by RNase H digestion of the targeted mRNA region annealed to a short DNA oligonucleotide. The length of the poly(A) tail of the 3' fragment is then determined by running the sample on a polyacrylamide gel, by electrophoretic transfer, by probing with a radiolabeled cDNA and by comparing the size of the detected region with a specific RNA ladder or a DNA ladder.