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tophat- paired end reads combined in one file

Hi All,

Just a quick question re tophat- How does tophat handles the paired-end data when both the reads (left and right) are in one file. I mapped this data (still running) using tophat without separating the paired-end reads in two different files. Will top handle this or I should separate the files?

Thanks,RT

rna-seq tophat

1 answer

You should separate the FASTQ reads into two files for Tophat. It will not recognize them as paired-end reads if they are together in the same file.

From the manual:

##Using TopHat

Usage: `tophat [options]* <genome_index_base> <reads1_1[,...,readsN_1]> [reads1_2,...readsN_2]`

When running TopHat with paired reads it is **critical** that the `*_1` files an the `*_2` files appear in separate comma-delimited lists, and that the order of the files in the two lists is the same.

Thanks, Does any quick script exists to do this?

Done. Thanks!

Just out of curiosity, which tool did you use to successfully accomplish this? I haven't had to do such a thing yet, but I'm sure I will at some point and it would be nice to know what works.

Deedee, I wrote my own python script. I tried to use grep but it does not print the quality line in the new file. I don't know why.

grep -A 3 '/1' test.fastq > test_leftreads.fastq

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