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Hello,
I'm analyzing some Illumina data 35 bp reads that I got from SRA to get some practice analysing NGS data. When I do some QC using FASTQ, I get a distribution of several kmers that I can't explain. I have attached an image. Is it possible that the peaks from 18-24 are part of a an adapter? If so, I would expect the kmer peaks to extend up to position 31. There is also a rise in 'AAAAA' 5mers that peaks at 13 and suddenly drops off. There are 10 samples from this data set and all have very similar results.
Any insight would be appreciated.
I'm analyzing some Illumina data 35 bp reads that I got from SRA to get some practice analysing NGS data. When I do some QC using FASTQ, I get a distribution of several kmers that I can't explain. I have attached an image. Is it possible that the peaks from 18-24 are part of a an adapter? If so, I would expect the kmer peaks to extend up to position 31. There is also a rise in 'AAAAA' 5mers that peaks at 13 and suddenly drops off. There are 10 samples from this data set and all have very similar results.
Any insight would be appreciated.