Dynamic Evolution of Poly-A Tail Lengths Visualized by RNAse H Assay and Northern Blot Using Nonradioactive Probes in...

Poly-A tail length dynamics have been extensively studied from yeast to human, mostly using reporter transcripts. Recent studies have been carried out genome-wide to determine the status of poly-A tails at steady state. However, poly-A tail measurement at equilibrium gives an overall length that reflects a mixture of the different poly-A tail sizes for a single transcript. New genome-scale techniques are emerging to estimate dynamic of poly-A tails lengths, but they are not yet routine and individual validation experiments are useful. In this chapter we describe a protocol for visualizing poly-A tail lengths following transcription inhibition for a reporter mRNA using denaturing poly-acrylamide gel electrophoresis and northern blot assay. This protocol is quick to set up, requires the purchase of only a few specific reagents, does not rely on radioactivity for RNA monitoring, and can be easily implemented in any molecular biology laboratory.