Melting temp of neucleotide sequence

[B Lauder]

Hi,

I wonder if anybody can help me out here - I'm a Biochemist but not a 
molecular biologist (That's not the problem) and I'm have a lot of 
diffuculty finding an equation for the estimation of the melting 
temeperature of a nucleotide sequence based upon G+C content and the 
[Na]. Obviously I've failed otherwise I'd not be posting this. 

I've tried a number of gereral textbooks to no avail. The really annoying 
thing is that I know I've seen such an equation but I just can't remeber it - 
I do recall the Tm was dependant upon the log[Na] I think. 

Anyway, any help - pointers or an equation ? Thanks 

Bob. 
-- 
Biological Sciences, Lancaster University, UK # 
R.Lauder at Lancaster.ac.uk
http://bssv01.lancs.ac.uk/gig/ppl/bob/home.htm