Let's say I've run the PCR and I now have a certain amount of the amplicon product. Is there any model that infers how much of it was there before the PCR started? I suspect it should be a probabilistic model (a distribution) parameters (shape) of which will strongly depend on the details of the PCR protocol and the characteristics of the amplicon...
If not, then may be there are forward models that predict the amount of the amplified result from the initial content?