Ideal number of copies in positive control

[alvaro.guerrero]

We have bought a set of 4 linearised plasmids with different insert targets to be used as positive controls for respiratory viruses. We use a 7500 Applied Biosystems instrument and for most of these viruses we run a singleplex assay but for some of them we run a multiplex assay. The assay is used in a qualitative way (yes-no answer) Is there a desired number of copies per PCR input for those viruses run singleplex? what factors should be considered to prepare positive controls for multiplex assays?

It would be very helpful if anybody could give some information on how to prepare this positive controls from plasmids as I am a little bit lost.

Thanks

[namishu95]

100-1000 copies/ul should be better,