Figure 3. Kinetics of amplification of KGA and LGA and their competitors.

(A) KGA cDNA (0.50 pg, from medullar blood cells) and the corresponding molar amount of its competitor (0.28 pg) were added to a PCR reaction mixture, together with [α-³²P]dCTP. Following 20, 26, 33 and 40 amplification cycles 10 μl of the reaction was removed and the products were resolved on a 1.5% agarose/ethidium bromide gel. Following gel electrophoresis, the bands corresponding to the KGA transcript (○) and competitor (●) were excised from the gel and the amount of radioactivity in each band was determined by scintillation counting. The amount of PCR product (as radioactivity) was plotted as a function of cycle number. (B) LGA cDNA (5 pg from medullar blood cells) and the corresponding molar amount of its competitor (3.75 pg) were added to a PCR reaction mixture, together with [α-³²P]dCTP. The same procedure was carried out for the determination of the amount of the respective PCR products.