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How to make the Reverse sequence from single forward sequences Illumina Hiseq?

Hello,

I am working with Illumina hiseq 2000, only single reads. I got my sequences from the EBI database:https://www.ebi.ac.uk/ena/data/view/PRJEB15445

I'm planning on doing some further analysis and for that I need pair-end sequences. I need to artificially generate the reverse reading. I am bit confused because I've read in different resources that stated that the Reverse sequence is only the reverse and in others that it is the reverse-complement. I was wondering if someone knows if the second read is only the reverse or the reverse-complement?

Thank you so much

illumina

1 answer

You can't generate paired-end data after the fact (from single end data), if the original sequencing was not done as paired-end. If you were to create a reverse complement of the reads at hand there will be a perfect overlap between the two without spatial information that a normal paired-end read gives (see illustration below).

R1 ---------------------->
   -------------------------------------------------------------------------------
                                                           <---------------------- R2

Thanks for your response. I was confused with the R2 output in pair end. I thought it was reverse complement but that is incorrect it's only the reverse. If I do the reverse of my fastq sequences for my single read data, I think that would work, or not?

It's reverse complement, because in order to go in the 5' to 3' direction, R2 is read from the opposite strand.

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