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_12_s456.fastq.gz zr1394_12_s456.fastq.gz Processing reads on 1 core in single-end mode ... Finished in 1473.69 s (24 us/read; 2.45 M reads/minute). === Summary === Total reads processed: 60,153,246 Reads with adapters: 336,528 (0.6%) Reads written (passing filters): 58,592,940 (97.4%) Total basepairs processed: 3,025,392,455 bp Quality-trimmed: 3,279,045 bp (0.1%) Total written (filtered): 2,374,832,701 bp (78.5%) === Adapter 1 === Sequence: AGATCGGAAGAGC; Type: regular 3'; Length: 13; Trimmed: 336528 times No. of allowed errors: 0-9 bp: 0; 10-13 bp: 1 Bases preceding removed adapters: A: 27.7% C: 1.4% G: 32.7% T: 38.2% none/other: 0.0% Overview of removed sequences length count expect max.err error counts 3 262474 939894.5 0 262474 4 61259 234973.6 0 61259 5 6868 58743.4 0 6868 6 674 14685.9 0 674 7 2225 3671.5 0 2225 8 853 917.9 0 853 9 404 229.5 0 34 370 10 865 57.4 1 10 855 11 211 14.3 1 23 188 12 104 3.6 1 3 101 13 36 0.9 1 0 36 14 27 0.9 1 0 27 15 31 0.9 1 0 31 16 104 0.9 1 0 104 17 243 0.9 1 0 243 18 123 0.9 1 0 123 19 15 0.9 1 0 15 20 4 0.9 1 0 4 22 2 0.9 1 0 2 24 1 0.9 1 0 1 25 3 0.9 1 0 3 26 1 0.9 1 0 1 30 1 0.9 1 0 1