This is cutadapt 2.10 with Python 3.6.7 Command line parameters: -j 1 -a AGATCGGAAGAGC -u 10 -u -10 -q 20 -m 30 -O 3 -o fastq/zr1394_11_s456.fastq.gz zr1394_11_s456.fastq.gz Processing reads on 1 core in single-end mode ... Finished in 1086.71 s (20 us/read; 3.04 M reads/minute). === Summary === Total reads processed: 55,109,528 Reads with adapters: 790,827 (1.4%) Reads written (passing filters): 45,040,683 (81.7%) Total basepairs processed: 2,769,826,173 bp Quality-trimmed: 15,587,339 bp (0.6%) Total written (filtered): 1,385,633,479 bp (50.0%) === Adapter 1 === Sequence: AGATCGGAAGAGC; Type: regular 3'; Length: 13; Trimmed: 790827 times No. of allowed errors: 0-9 bp: 0; 10-13 bp: 1 Bases preceding removed adapters: A: 26.4% C: 1.3% G: 30.3% T: 42.1% none/other: 0.0% Overview of removed sequences length count expect max.err error counts 3 534175 861086.4 0 534175 4 208482 215271.6 0 208482 5 14739 53817.9 0 14739 6 15945 13454.5 0 15945 7 6079 3363.6 0 6079 8 956 840.9 0 956 9 2584 210.2 0 875 1709 10 5159 52.6 1 77 5082 11 2347 13.1 1 25 2322 12 273 3.3 1 0 273 13 83 0.8 1 0 83 14 1 0.8 1 0 1 15 2 0.8 1 0 2 17 1 0.8 1 0 1 18 1 0.8 1 0 1