SRR837839

This is a bulk RNA-seq run (Illumina Genome Analyzer IIx, human) that fails QC at 31/100 (grade F), and the verdict is driven overwhelmingly by base-call quality rather than library artifacts. The decisive negatives are pct_q30_bases at 31.1% (only ~31% of bases meet Q30) and a mean base quality of just 15.6 — both scored 0/100 — meaning the majority of base calls carry a high error probability, which directly undermines variant calling and confident read mapping and would inflate spurious mismatches in expression quantification; the very short 36 bp reads further compound multi-mapping ambiguity. On the credit side, adapter content is effectively zero (100/100) and the 36.45% duplication rate is acceptable for RNA-seq (86/100), so the problem is intrinsic sequencing quality, not contamination or over-amplification, consistent with this being an older first-generation Illumina platform. Notably, evidence_strength is 1, so while the QC-driving quality metrics are genuinely measured, the read/base totals are only reported — the headline grade is trustworthy for the quality call but a fuller measured pass is still warranted; overall I would not reuse this dataset where base accuracy matters (variant detection, allele-specific or precise quantitative analysis).