This is cutadapt 2.10 with Python 3.6.7 Command line parameters: -j 1 -a AGATCGGAAGAGC -u 10 -q 20 -m 36 -O 3 -o fastq/zr1394_17_s456.fastq.gz zr1394_17_s456.fastq.gz Processing reads on 1 core in single-end mode ... Finished in 1081.37 s (25 us/read; 2.37 M reads/minute). === Summary === Total reads processed: 42,730,485 Reads with adapters: 288,438 (0.7%) Reads written (passing filters): 41,281,874 (96.6%) Total basepairs processed: 2,143,526,203 bp Quality-trimmed: 2,426,682 bp (0.1%) Total written (filtered): 1,671,155,887 bp (78.0%) === Adapter 1 === Sequence: AGATCGGAAGAGC; Type: regular 3'; Length: 13; Trimmed: 288438 times No. of allowed errors: 0-9 bp: 0; 10-13 bp: 1 Bases preceding removed adapters: A: 29.3% C: 2.3% G: 34.5% T: 33.9% none/other: 0.0% Overview of removed sequences length count expect max.err error counts 3 232120 667663.8 0 232120 4 41316 166916.0 0 41316 5 7514 41729.0 0 7514 6 691 10432.2 0 691 7 1822 2608.1 0 1822 8 1037 652.0 0 1037 9 422 163.0 0 61 361 10 920 40.8 1 8 912 11 430 10.2 1 86 344 12 212 2.5 1 0 212 13 150 0.6 1 0 150 14 130 0.6 1 0 130 15 174 0.6 1 0 174 16 371 0.6 1 0 371 17 670 0.6 1 0 670 18 373 0.6 1 0 373 19 49 0.6 1 0 49 20 10 0.6 1 0 10 21 1 0.6 1 0 1 22 5 0.6 1 0 5 23 9 0.6 1 0 9 24 2 0.6 1 0 2 25 4 0.6 1 0 4 26 4 0.6 1 0 4 27 2 0.6 1 0 2