forward & reverse primers - (Nov/09/2006 )
I want to know what do we mean by forward & reverse primers in PCR & sequencing reactions. I also want to know why are forward primers & reverse primers named so?
let's take a gene. It's always written from 5' to 3'
there is also a complementary sequence, because DNA is double stranded.
if you wout to do a PCR, you need to enhance both strands, so you need a primer for one strand, called the forward primer, which is the beginning of your gene, and an other primer that will begin the complementary strand (in the 5' end), it's called the reverse primer.
You can call them also sense and antisense. It is the result of antiparallel arrangement of the DNA and important for the sequence-reading preferences of enzymes.
I am not sure where did I hear it from. Apparently, the sense and antisense are pretty much mixed up in different countries. Some will call sense as forward while others might call sense as reverse.
So I think it is better to stick with forward and reverse. Sorry if I got this info wrong.