FAQ: Can I end-label a polyadenylated RNA molecule with a Cy3/5 or biotin-modified base using the E. coli Poly(A) Polymerase?

Yes. Biotin-ATP can be incorporated efficiently by the Poly (A) Polymerase. Cy3/5 modified bases can also be incorporated, but at a lower efficiency. The tailing length and biotin density can be controlled by optimizing the reaction time, the ATP/biotin-ATP ratio and the total ATP concentration.