Figure 2.
Linearity and sensitivity of two-step RT-PCR for quantification of transferrin receptor gene expression in total RNA from blood CD4+ cells. The number of preamplification cycles in the multiplex step was consistently and inversely related to cycle threshold for transferrin receptor gene in the real-time PCR step. Each real-time PCR contained an equivalent of 0.05% of starting RNA (88 pg to 5.0 fg). Finally, transferrin receptor gene could be quantified using as little as 5.0 fg of starting total RNA. In this instance, the optimal range for multiplex PCR amplification was 10–25 cycles.
