Figure 1.

RT-PCR is a semi-quantiative method for measuring IL-5 mRNA expression. PBMC were incubated with or without PMA (50 nm) and PHA (5 μg/ml) and RNA was harvested at 6 hr for semi-quantitative RT-PCR analysis of IL-5 and GAPDH. Complementary DNA samples from the reverse transcriptase reaction were pooled to create an average sample. Dilutions of that average sample (1, ½, ¼) as well as negative controls for both the reverse transcriptase reaction (No RNA) and the PCR (No cDNA) were always used for every PCR and subsequent gel run. A representative agarose gel is shown with corresponding optical density data to demonstrate linearity of the technique. λ = IL-5 (R² = 0·97), ν = GAPDH (R² = 0·99).