problem with fastq input #43

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jchenpku opened this Issue Mar 6, 2017 · 2 comments

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jchenpku commented Mar 6, 2017

I have a fastq file like this, it's from a crispr screening:
@ERR376999.1 1/1
CCTGACAGTCTCCCGCGCT
+
EEEEEFFEFEEFEEEEEEF
@ERR376999.2 2/1
CATTTATTTTTCGGAGTGC
+
EEEEEEFEEFEEEEEFEFF
@ERR376999.3 3/1
AGTTCAAAATCCAGTCTAC

The file can be aligned with bowtie2 without any problem but when I'm trying to align it using bowtie, it reported error:
Saw ASCII character 10 but expected 33-based Phred qual.

I tried the untrimmed fastq file, it also reported error:
Error: reads file does not look like a FASTQ file

the untrimmed file looks like this:
@ERR376999.1 1/1
CTTGTGGAAAGGACGAAACACCGCCTGACAGTCTCCCGCGCTGTTTTAGA
+
B@CDDDDEEEEEEEEEEEEEEFEEEEEEFFEFEEFEEEEEEFEEEEEDED
@ERR376999.2 2/1
CTTGTGGAAAGGACGAAACACCGCATTTATTTTTCGGAGTGCGTTTTAGA
+
B@CDDDDEDEEEEEEEEEEEFFFEEEEEEFEEFEEEEEFEFFEEEFFEEE
@ERR376999.3 3/1
CTTGTGGAAAGGACGAAACACCGAGTTCAAAATCCAGTCTACGTTTTAGA

what could be the problem? Thanks

dnbh commented Mar 6, 2017 edited

Your sequence and quality scores are of different lengths, both trimmed and untrimmed. These are malformed fastq files and any reasonable program will refuse to process them.

Character "10" is the newline character; it is expecting your reads' quality and sequence fields to be of the same length and is finding that the line ends too soon.

Owner

BenLangmead commented Apr 25, 2017

Could you share the file that gives bowtie the problem? Or ideally just a small part of the file that causes the problem?

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