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_10_s456.fastq.gz zr1394_10_s456.fastq.gz Processing reads on 1 core in single-end mode ... Finished in 1471.12 s (19 us/read; 3.23 M reads/minute). === Summary === Total reads processed: 79,264,583 Reads with adapters: 1,411,423 (1.8%) Reads written (passing filters): 63,636,423 (80.3%) Total basepairs processed: 3,978,999,570 bp Quality-trimmed: 24,230,063 bp (0.6%) Total written (filtered): 1,956,753,478 bp (49.2%) === Adapter 1 === Sequence: AGATCGGAAGAGC; Type: regular 3'; Length: 13; Trimmed: 1411423 times No. of allowed errors: 0-9 bp: 0; 10-13 bp: 1 Bases preceding removed adapters: A: 25.9% C: 1.0% G: 31.6% T: 41.6% none/other: 0.0% Overview of removed sequences length count expect max.err error counts 3 946719 1238509.1 0 946719 4 383449 309627.3 0 383449 5 23302 77406.8 0 23302 6 23846 19351.7 0 23846 7 11214 4837.9 0 11214 8 1466 1209.5 0 1466 9 5476 302.4 0 1724 3752 10 10795 75.6 1 159 10636 11 4549 18.9 1 49 4500 12 537 4.7 1 0 537 13 69 1.2 1 0 69 15 1 1.2 1 0 1