R is purine, so either A or G. If you order the oligo with the R in the sequence, they will produce a 50:50 mix of A:G containing oligos

R is purine, so either A or G. If you order the oligo with the R in the sequence, they will produce a 50:50 mix of A:G containing oligos

Thank you for this answer

Dear Mamadou,

The symbol R indicate that the primer you are interested in is a "Degenerate" primer. It mean, when you order the primer with single R symbol in it sequences - the company will make a mixture of two different primers, in which in the "R" position is either "A" or "G" as explain by Amanda...

For example, if the primer sequences you order from oligo-company is "---acRgt---", then the company will make a mixture of two primers consisting of "---acAgt---" and "---acGgt---", respectively.

I hope this will add some information for you. Good luck...