GC Content measurement - (Mar/03/2011 )

Hello
I want to know how to measure the GC content of a DNA ?
Is it done spectrophotometrically ?
Long ago, I saw somebody analysing the DNA by increasing temperature and taking its OD at each degree rise in spectrophotomer, but dont know what was that..
please help me to know more.
thanks..

Did you check this: http://en.wikipedia.org/wiki/GC-content

Its nothing special, so I think this general info can help you allready a lot.

well thanks. thats what I am asking..
I tried to search on Schimadzu instruments, but could not find the spectrophotometer with heating facility..

Easiest is to find a quantitative PCR machine, and do a melting curve on the DNA using sybr-green dye. Old school -- you can cut the DNA into monomers and run an HPLC that separates the four bases. New school -- sequence the whole genome with an Illumina and count bases.

microbes on Sat Mar 5 10:23:30 2011 said:

I do not know if you ever did a sequence ananlysis, but as phage434 just said: nowedays most people just send their sample to sequence it... (or they do it themself if they can).
Or maybe there is allready some information avaible of that specific DNA you want to research.

I think this option is the easiest one and perhaps the cheapest one since it doenst involve much work and its the most accurate one. And reading your reply it seems you dont have the correct equipment to check it yourself.

BTW: why do you want to know the GC content? just for the melting temperature?