SRR2105509

This is a deeply duplicated, adapter-saturated short-read ncRNA-Seq library from human (Illumina Genome Analyzer), and despite pristine per-base quality it earns a marginal D because the metrics that matter most for reuse are failing. On the upside, base accuracy is excellent — pct_q30 of 97.7% and a mean base quality of 38.3 mean the underlying basecalls are trustworthy, and the near-zero N content and 52.5% GC raise no compositional alarms. The grade is dragged down by two heavily weighted, directly measured failures: an adapter_content of 96.31% (essentially every read is adapter-contaminated and must be aggressively trimmed before any alignment, with the short 51 bp reads at real risk of being whittled to unusable lengths) and an 84.76% duplication_rate (very low library complexity, so quantification will be dominated by a small set of distinct molecules and expression estimates will be unreliable). Note that evidence_strength is 1 (the highest), so this is a fully measured read rather than a provisional one — the verdict is solid: the high-quality bases are real, but so is the contamination, and you should expect substantial read loss after trimming and treat any abundance estimates with caution.