The best description of quantitative RT-PCR i have come accross is to be found
in Huet et al Development 118 p613 (1993) and Development 121 p1195 (1995).
Francois has established conditions for PCRing from as little as a fiftieth of
a single salivary gland. His conditions and primers are all described in the
Dept of Genetics
University of Cambridge
SR120 at mole.bio.cam.ac.uk