This calculation is based on
the
assumption that the average weight of a base pair (bp) is 650
Daltons. This means that one mole of a bp weighs 650 g and
that the molecular weight of any double stranded DNA template can be
estimated by taking the product of its length (in bp) and
650.
The inverse of the molecular weight is the number of moles of
template present in one gram of material.
Using Avogadro's number, 6.022x1023 molecules/mole, the
number of molecules of the template per gram can be calculated:
mol/g * molecules/mol = molecules/ g
Finally, the number of molecules or number of copies of
template
in
the sample can be estimated by multiplying by 1*109 to
convert to ng
and then multiplying by the amount of template (in ng)
This calculator requires the user to input the amount of a template
present (in ngs) and the length of the template (in bp) and with
this information the number of copies of the template is calculated.
The formula used is:
number of copies = ( amount * 6.022x1023) / (length * 1x109 *
650)
number =
(ng * number/mole) / (bp * ng/g * g/ mole of bp)
Created by Andrew Staroscik
29 January 2004