Entering edit mode
Dear Daniel,
The guidelines are the same for miRNA-seq as for RNA-seq. At its
simplest, you simply need a reasonable minimum number of counts in at
least some samples. At a minimum, I think you would want at least 5
counts, maybe more, in each sample in which the gene in expressed.
So, if your sequencing depth is about 20 million reads per sample, you
might ask for cpm>0.3 (equivalent to 6 reads). If your sequence depth
is
10 million read per sample, you might ask for cpm>0.6 (again
equivalent to
6 reads). It's not rocket-science. It's all quite rough as the exact
cutoff isn't important.
Best wishes
Gordon
> Date: Thu, 19 Jun 2014 10:10:36 +0000
> From: Daniel <daniel.nicorici at="" gmail.com="">
> To: <bioconductor at="" stat.math.ethz.ch="">
> Subject: Re: [BioC] total count filter cutoff (edgeR)
>
>
> Gordon K Smyth <smyth at="" ...=""> writes:
>
>>
>> Hi Mahnaz,
>>
>> Why don't you follow the advice of the edgeR User's Guide (as Mark
has
>> suggested)? All the case studies in the User's Guide describe how
the
>> filtering was done in a principled way.
>>
>> Total count filtering is not so bad, but it is susceptible to being
driven
>> by one library, especially by one library with a large sequence
depth.
>> The procedure described by Mark and used in the guide is a
compromise of
>> several considerations.
>>
>> BTW, there are newer versions of R and edgeR available than what
you are
>> using.
>>
>> Best wishes
>> Gordon
>>
>
>
> Hello,
>
> in case that one has miRNA (i.e. microRNA) data what is a good
suggestion
> for the cpm cutoff? Is it the same like for RNA-seq?
>
> I have not found a recommendation/case/example in the edgeR
manuals/guides
> for miRNA-seq data analysis.
>
>
> Best Wishes,
> Daniel
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