Copy number quantitation- PCR

[Daraporn Pittayakhachonwut]

Dear colleagues,

How do people quantitate/ titrate DNA copy numbers to ie, 1 copy number?
There should be some form of pipetting error or band intensity variation
in ie, semi-quantitative PCR right? How are these standardized?

If one wants to determine the copy number of a gene in PCR, what does one
do? How does one differentiate between ie, 5 and 10 copies? 5000 copies?

Please answer to my e-mail account : 

g3736281 at mucc.mahidol.ac.th

since I don't have access to usenet often.

Thank you very much -

Sincerely yours,

Daraporn 
g3736281 at mucc.mahidol.ac.th