N6-propargyl-adenosine (N6pA) can be used to measure de novo mRNA poly(A) tail synthesis in proliferating cells. N6pA is cell permeable and incorporates into nascent mRNA transcripts both transcriptionally by RNA polymerase I, II and III and posttranscription-ally by poly(A) polymerase instead of their natural analolg adenosine. The resulting ethynyl-functionalized RNA can subsequently be detected via Cu(I)-catalyzed click chemistry that offers the choice to introduce a Biotin group (via Azides of Biotin) for subsequent purification tasks or a fluorescent group (via Azides of fluorescent dyes) for subsequent microscopic imaging.
