The QIAseq Single Cell RNA Library Kit UDI is a complete cell-to-library solution that generates RNA-seq libraries from single eukaryotic cells or from picogram levels of purified RNA. The kit contains reagents for the efficient lysis of isolated single cells or populations of cells from common cell-sorting or cell-isolation platforms. After lysis, genomic DNA is degraded and reverse transcription is performed. This reaction can be primed using oligo-dT primers to enrich for polyadenylated RNAs, random primers with QIAseq FastSelect for full transcriptome coverage without rRNA, or you can use your own primers to enrich for specific small RNA genomes, like a virus, for sequencing. After reverse transcription and second strand synthesis, a ligation step generates a long, double-stranded cDNA template which is amplified via MDA using the high-fidelity, proofreading REPLI-g SensiPhi DNA Polymerase. This generates microgram amounts of amplified cDNA, some of which can be stored for later use or confirmatory testing. Amplified cDNA is fragmented using QIAGEN’s FX enzymatic fragmentation reaction, generating inserts compatible with common sequencing read lengths. By changing the fragmentation conditions, the insert size can be varied according to individual preferences. The reproducible amplification reaction excludes the need for quantification of the cDNA prior to fragmentation. The fragmented DNA is end-polished and subjected to a highly efficient ligation reaction with the included QIAseq Unique Dual-Index Y-Adapter Kits. Amplification of the library with PCR is not necessary, so the production of PCR duplicates is avoided, and library diversity remains high.