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Wrong (low quality) bases in overlapped regions failed to be corrected

Open drna opened this issue 8 years ago • 4 comments

AfterQC has helped me to improve the quality of my data. Thanks for creating it.

I did notice, though, that some wrong (low quality) bases in overlapped regions failed to be corrected and I am not sure why.

Could you perhaps have a look, below one read as an example. ---------------- test_R1.fastq @NS500261:202:HKMTKAFXX:1:21112:5370:11983 1:N:0:ATCTAGCCGGCC CTGCGCCTGGTTGGGCATCGCTCCGCTAGGTGTCAGCGGCTCCACCAGCTGGGGTGAGGGGGTGGTGGGTCAGTGCTGGGGGCCGGTGCAGACCCCACGCGGGCTGGGAGGACTTCACCCCGCCTCACCTCCGTTTCCTGCAGATCGGAAG + AAAAAEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEAEEAEEAEEEEEEEEEEEEEEEEEE/EEEE/EEEEEEEEEEEAEE/AA<AAEEAAAAAEE<EAAA<A<6AAAAE<<AEAAAAAEE ---------------- test_R2.fastq @NS500261:202:HKMTKAFXX:1:21112:5370:11983 2:N:0:ATCTAGCCGGCC GCAGGAAACGGAGGTGAGGCGGGGTGAAGTCCTCCCAGCCCGCGTGGGGTCTGCACCGGCCCCCAGCCCTGACCCACCACCCCCTCACCCCAGCTGGTGGAGCCGCGGCCCCCTAGCGGCGCGATGCCCAACCAGGCGCAGAGCTC + AAAAAEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEAEEEEEEEEEEEEEEEEEEEAEEEEEEE/AE/E/E/EEE/EE/EEEEE/EAE6EE/EE//E/E//EEE/A/A/E/AE/AAE/E/EE</<AAEE//AE//<E6E////6<<

drna avatar Jul 19 '17 12:07 drna

This pair of reads have too many mismatches (5 in total).

AfterQC will skip correcting the overlaps with mismatches > 3. This is to avoid over-correction.

sfchen avatar Jul 19 '17 12:07 sfchen

It makes sense! Can the threshold be adjusted?

drna avatar Jul 19 '17 12:07 drna

I will update AfterQC to make it adjustable.

sfchen avatar Jul 19 '17 12:07 sfchen

Fantastic! Thanks

drna avatar Jul 19 '17 12:07 drna