Primers & adapters missing

[SoilRotifer (Mike Robeson)]

Hi @mayalmp, welcome to !

So what sequencing strategy was used to generate the data? For example, if you are using the sequencing strategy as outlined via the Earth Microbiome 16S rRNA gene Protocol then there may not be any primers in the generated sequence data.

More details can be found here:

Trimming and joining short reads resulted in few merged read on v4 region

Hi @simon, If you are indeed sequencing via a 2x150 kit with the EMP V4 (515f-806r primers), and those primers are actually contained within the reads… then sadly these reads will either be to short, or not have enough enough high-quality bases, for merging. The 2x150 sequencing approach works best when using the sequencing strategy outlined here, and the references therein. That is, when using a 2x150 for the V4 region, the sequencing strategy used should NOT sequence through the primers. Mea…

-Mike