Is the trimming after the barcode in process_10xReads necessary?

[alxsimon]

Hi,
in process_10xReads the default for the --trim option is 7bp.

I was wondering why this was set up in the first place as it is not indicated in the README.
Does it change a lot to the final quality if I set it to 0?
As 7bp feels like a lot of data being left behind.

Thanks!
Alexis

[alxsimon]

Sorry, in fact I digged a little bit in the code and realised the trimmed fragment is stored and reattached during the regen step.

But I am still interested in knowing why it needs to be trimmed, is there another barcode there?

[msettles]

Thats the random primer sequence and not actual genome sequence, its also not very complex sequence

[alxsimon]

Thanks for your answer.