Why are poly-A sequences overrepresented in RiboMinus library preps?

[ExMachina]

A simple question that google cannot find me an answer to.

I have 40 fully sequenced 50SE RiboMinus prepared libraries and none show (according to FastQC) any poly-A overrepresentation. Is this filtered out at some stage?

Thanks for any info or references.

EDIT: I mis-typed the title of the thread and can't see how to correct it.

[nucacidhunter]

I guess 1st strand was synthesized using randome primers. In this case chance of having polyT primers to prime polyA regions would be low. Other reason could be low proportion of polyA RNA in the sample.

[nucacidhunter]

Title of the post is also contradictory to text.

[ExMachina]

I guess 1st strand was synthesized using randome primers. In this case chance of having polyT primers to prime polyA regions would be low. Other reason could be low proportion of polyA RNA in the sample.

Yes. First potential cause makes sense. Second potential cause was my worry Thanks.

Title of the post is also contradictory to text.

How so? I mis-typed it originally but tried to correct immediately--is it showing up wrong?

EDIT, why yes it is shwing up wrong! There seems to be no way to correct that I guess?