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_1_s456.fastq.gz zr1394_1_s456.fastq.gz Processing reads on 1 core in single-end mode ... Finished in 1209.93 s (26 us/read; 2.35 M reads/minute). === Summary === Total reads processed: 47,399,413 Reads with adapters: 287,836 (0.6%) Reads written (passing filters): 46,105,584 (97.3%) Total basepairs processed: 2,382,626,805 bp Quality-trimmed: 2,209,670 bp (0.1%) Total written (filtered): 1,868,666,820 bp (78.4%) === Adapter 1 === Sequence: AGATCGGAAGAGC; Type: regular 3'; Length: 13; Trimmed: 287836 times No. of allowed errors: 0-9 bp: 0; 10-13 bp: 1 Bases preceding removed adapters: A: 27.1% C: 2.2% G: 35.0% T: 35.7% none/other: 0.0% Overview of removed sequences length count expect max.err error counts 3 227679 740615.8 0 227679 4 45938 185154.0 0 45938 5 6341 46288.5 0 6341 6 633 11572.1 0 633 7 1721 2893.0 0 1721 8 731 723.3 0 731 9 359 180.8 0 43 316 10 834 45.2 1 18 816 11 428 11.3 1 46 382 12 262 2.8 1 4 258 13 128 0.7 1 0 128 14 120 0.7 1 0 120 15 194 0.7 1 0 194 16 467 0.7 1 0 467 17 1124 0.7 1 0 1124 18 731 0.7 1 0 731 19 93 0.7 1 0 93 20 14 0.7 1 0 14 21 7 0.7 1 0 7 22 5 0.7 1 0 5 23 4 0.7 1 0 4 24 6 0.7 1 0 6 25 4 0.7 1 0 4 26 5 0.7 1 0 5 27 5 0.7 1 0 5 28 3 0.7 1 0 3