On the other hand, while libraries generated by IVT can avoid PCR-induced sequence bias, specific sequences may be transcribed inefficiently, thus causing sequence drop-out or generating incomplete sequences.[22][2] Several scRNA-Seq protocols have been published: Tang et al.,[23] STRT,[24] SMART-seq,[25] CEL-seq,[26] RAGE-seq,[27] , Quartz-seq.[28] and C1-CAGE.[29] These protocols differ in terms of strategies for reverse transcription, cDNA synthesis and amplification, and the possibility to accommodate sequence-specific barcodes (i.e. UMIs) or the ability to process pooled samples.[30]