general pcr/primer question - (Nov/28/2006 )

what does it mean when you design primers to span introns? what purpose does that serve? is it so you don't amplify DNA or pre transcriptional sequence?

it means the primer starts in exon n, and part of the sequence is in exon n+1 or n+2 (depending on the size of the primer and exon).
it stops PCR amplification of genomic DNA, or pre-transcriptional sequences.
it's rather nifty.

V