Poly(A)-ClickSeq is a specific variant of ClickSeq that uses an Oligo-dT primer in the Reverse transcription step. cDNA fragments are thus focused to the 3’ ends of polyadenylated RNAs, such as metazoan mRNAs and viral genomic RNAs. As such, Poly(A)-ClickSeq provides a powerful platform for transcriptomics and differential gene expression analysis. Since only one NGS read is obtained per molecule of mRNA in a sample, the bioinformatics procedures are greatly simplied and the amount of sequence depth is greatly reduced (~10M reads required vs 100M per sample for a typical transcriptomics study). Additionally, Poly(A)-ClickSeq can be used to precisely map the junction of a poly(A)-tail within the 3’UTR of a mRNA. As such, it is an excellent tool for studying alternative polyadenylation and alternative 3’ exon usage.

Poly(A)-ClickSeq retains all the advantages of ClickSeq, such as the removal of fragmentation steps and a simplified workflow. In addition, Poly(A)-ClickSeq does not require any ribo-depletion or mRNA enrichment prior to the library prep, since the Oligo-dT primer automatically enriches for mRNAs and other species of interest. In some cases, Poly(A)-ClickSeq can even be performed directly on cells, without RNA extraction.