should the forward sequence data have the exactly same size as reverse?

I found my sequence data like this:
NHD2153_L1_3#A.raw-r1.fq(50594kb) from NHD2153_L1_3#A.raw_1.fq.gz(12122kb)
NHD2153_L1_3#A.raw-r2.fq(50594kb) from NHD2153_L1_3#A.raw_2.fq.gz(14641kb)
the forward and reverse sequence data of one sample have the same size after unzip.
I don’t know why? Is it right?? Did have some problem?

Hi @yhuizhen,

the easy explanation is that forward and reverse read files contain sequences which are of same length, which probably means they are raw sequences coming out from the machine. For quality/adapter trimmed sequences I would expect slightly different lengths, hence different file sizes for forward and reverse. If I am correct you should not be in any trouble!


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Yes! I misunderstood the source of my sequence data. Thanks for your explanation a lot.

Best wishes