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[Jka83]

Perhaps you can help me with this:


For real time pcr (detection of virus), one wants to measure the sensitivity of the assay by determining the minumun amount of viral copies per reaction that the assay is able to detect.
So, let´s say I have 8 ng/ul of target RNA in the sample (measured by nanospec). By using this formula (http://www1.qiagen.c...uantifying.aspx):
Transcript length: 75nucleotides
Concentration: 8 ng/ul = 8 x 10-9 g/ul
Calculation: (8 x 10-9 g/ul / [75x 340]) x 6.022 x 10e23 =about 1,8e11 molecules per ul

I dilute this by factor 10 up to 9 and I get 188 molecules per ul.

My PCR mix is 25ul that includes 2ul of this RNA sample. My assay is able to detect this dilution so can I say that the detection limit is 376 copies PER REACTION (I put 2 microliters and 2X 188/ul=376) or is the limit this 376 divided by the reaction volume of 25??
In many journals they always give the sensitivity of the assay in "copies per reaction"...

Thank you for your help!!