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_14_s456.fastq.gz zr1394_14_s456.fastq.gz Processing reads on 1 core in single-end mode ... Finished in 2060.42 s (23 us/read; 2.59 M reads/minute). === Summary === Total reads processed: 88,771,906 Reads with adapters: 422,618 (0.5%) Reads written (passing filters): 86,667,433 (97.6%) Total basepairs processed: 4,466,488,793 bp Quality-trimmed: 4,720,154 bp (0.1%) Total written (filtered): 3,512,613,531 bp (78.6%) === Adapter 1 === Sequence: AGATCGGAAGAGC; Type: regular 3'; Length: 13; Trimmed: 422618 times No. of allowed errors: 0-9 bp: 0; 10-13 bp: 1 Bases preceding removed adapters: A: 27.7% C: 1.7% G: 32.6% T: 38.1% none/other: 0.0% Overview of removed sequences length count expect max.err error counts 3 329982 1387061.0 0 329982 4 74709 346765.3 0 74709 5 9824 86691.3 0 9824 6 973 21672.8 0 973 7 2800 5418.2 0 2800 8 877 1354.6 0 877 9 531 338.6 0 40 491 10 1364 84.7 1 5 1359 11 364 21.2 1 35 329 12 159 5.3 1 0 159 13 64 1.3 1 0 64 14 55 1.3 1 0 55 15 65 1.3 1 0 65 16 204 1.3 1 0 204 17 375 1.3 1 0 375 18 242 1.3 1 0 242 19 21 1.3 1 0 21 20 4 1.3 1 0 4 21 2 1.3 1 0 2 25 1 1.3 1 0 1 27 2 1.3 1 0 2