Hi,

How can I merge two paired end fastq (R and L) to give a single fastq file ? For information, the sequencing run is 72 bp long and it contains a majority of small RNA (miRNA,...) so a lot of paired end reads will overlap.

For example here's two paired reads :

@HWUSI-EAS529:41:FC62YHFAAXX:8:1:7969:1330 1:N:0:GCCAAT
CTACGAAAGGGCACTTGGAATTCTCGGGTGCCAAGGAACTCCAGTCACGCCAATATCTCGTATGCCGTCTTCTGCT
+
IIIIIIIHIIHIIIIIIHHIIIHGIIIIEIIIIIIEIIHIIIIIIIIIIIHIIIIIBHIHIIHGIGIEGHHEGEEH
@HWUSI-EAS529:41:FC62YHFAAXX:8:1:7969:1330 2:N:0:GCCAAT
AGTGCCCTTTCGTAGGATCGTCGGACTGTAGAACTCTGAACGTGTAGATCTCGGTGGTCGCCGTATCATTAAAAAA
+
IIIIIIIIIIIIIIIIIIIIIIIDHIGIIIHIIIGHGIIIIIIIHHIHIIIIIIIIIHIIIIIIIIHIIGIIIIHI

I find the adapter in the first one:

Code:

EMBOSS_001         1 CTACGAAAGGGCACTTGGAATTCTCGGGTGCCAAGGAACTCCAGTCACGC     50
                                    |||||||||||||||||||||              
EMBOSS_001         1 ---------------TGGAATTCTCGGGTGCCAAGG--------------     21

EMBOSS_001        51 CAATATCTCGTATGCCGTCTTCTGCT     76

EMBOSS_001        22 --------------------------     21

but not in the second one

But I effectively found the overlap between the right read and the left read (using the reverse complement of it)

EMBOSS_001         1 --------------------------------------------------      0

EMBOSS_001         1 TTTTTTAATGATACGGCGACCACCGAGATCTACACGTTCAGAGTTCTACA     50

EMBOSS_001         1 -----------CTACGAAAGGGCACTTGGAATTCTCGGGTGCCAAGGAAC     39
                                |||||||||||||||                        
EMBOSS_001        51 GTCCGACGATCCTACGAAAGGGCACT------------------------     76

EMBOSS_001        40 TCCAGTCACGCCAATATCTCGTATGCCGTCTTCTGCT     76

EMBOSS_001        77 -------------------------------------     76

So my question is, how can I merge the two fastq files to produce a single fastq file?

Thanks,
N.