Hi.

This is a bit tricky to calculate, because we need to understand that DNA extraction may not yield 100% of viral dna. But to compare the data, it is ideal to follow extraction protocol meticulously.... regarding the amount of each reagent taken at different steps including elution volume. If you have extracted your DNA evenly among the samples, then you can follow this method to calculate viral copy number per gm tissue.

if x is volume of extracted dna from 50 mg tissue

and y is copynumber per ul of 100 times diluted DNA

then your copynumber per gram tissue is 2000*x*y

(100*x*y/50/1000)

Hi Ramgie

You used 1uL of template, so your data tells you the copies per uL

Since this is a 1:100 dilution, you need to times this by 100 to give copies per uL for undiluted material

Next, you need to know the volume (in uL) of liquid you homogenised the tissue into - times by this number to give the total number of copies in 50mg

To convert this to copies per gram, simply times by 20

All the best

Thanks Barry Atkinson and Siva Ramakrishna Uppalapati for your responses.

Ok, I got it except for the last part wherein you multiply it by 20? I'm a little bit confused on where did you get this value?

Hi Ramgie

50mg x 20 = 1 gram