Downloaded fastq from SRA, am I right in thinking it isn't interleaved paired-end reads?

Question

[jennxyzhang]

Downloaded fastq from SRA using fasterq-dump I used grep on a sequence identifier I pulled using head:

grep HWI-ST808:122:C1B50ACXX:2:1101:2426:2231 C1_p_K4me3.fastq

output:

@SRR1035416.1 HWI-ST808:122:C1B50ACXX:2:1101:2426:2231 length=51

+SRR1035416.1 HWI-ST808:122:C1B50ACXX:2:1101:2426:2231 length=51

If anyone can take a second to confirm that I have unpaired reads that would be amazing. Thank you for your time!!

Answer 1

[GenoMax]

This looks like a single-end dataset. So no, those are not "interleaved" reads. In older fastq files entire fastq header was repeated after the + separator in line 3 of a fastq record. That is what you are observing.

Edit: This dataset is from 2013.