Primer length question

[mysticalelement]

Hi everyone, I'm stuck on this homework question, I'm hoping you could give me some ideas for it.

"In most PCR protocols, the primer pair need only be around 20 nucleotides each in length and annealing temperature is usually 55C; but in site-directed mutagenesis, the primers are often much longer with lengths from 25 to 45 nucleotides and the annealing temperature is around 65C. Two reasons why the primers need to be longer for site-directed mutagenesis?"

The only thing I can think of is that the mutations need to be a fair way in from the ends any other suggestions

Thanks

[SebaQ]

Hope i'm on time already... but you shoul read this, the paper of the guys who created this mutation system on E. coli. Inside it's explained everything you need to know:

[Only registered users see links. ]

Hope it helps ^^!

If you still have some questions, feel free to ask or send me a private message

[kaierwen]

A very good material! Thanks!