SRR1647951

This is a small-RNA (miRNA-Seq) library from mouse, sequenced on an Illumina HiSeq 2500, earning a solid B (88/100). The reads are of excellent intrinsic quality — 95.1% of bases at Q30, a mean base quality of 37.7, and effectively zero adapter contamination after trimming — which means the sequencing chemistry and read calls themselves are highly trustworthy for downstream alignment and quantification. The single factor holding the grade back is a high duplication rate of 62.49% (scored just 28/100), which is the dominant driver of the deduction; note, however, that for a miRNA-Seq library this is expected and not necessarily a defect, since the small, finite repertoire of mature miRNAs and PCR amplification of short fragments naturally produce many identical reads, so judge it as a small-RNA assay rather than by standard mRNA-seq complexity expectations. Evidence strength is high here (all scored metrics are directly measured, not extrapolated), so the QC verdict is firm rather than provisional, and the dataset is reasonable to reuse for miRNA expression profiling provided you handle duplicate reads appropriately for that assay type.