RT-PCR analysis of defensin mRNA expression by primary epithelial cells. Primary epithelial cells were obtained from human nasal turbinates (HNT), as described in Methods. The cells (5 × 106) were grown in the six well plates for 48 hours. The cells were then exposed to either the latex beads or A. fumigatus organisms for 18 hours. The mRNA was then isolated by TRIzol Reagent and RT-PCR was performed as described above in Materials and Methods. Specific primer pairs (Table 1) were used for RNA amplification. The sizes of amplified products are indicated and were as predicted. The hBD2 and hBD9 products were sequenced and confirmed to be identical to the predicted sequence. GAPDH was uniformly expressed. Cells in a control well were cultivated in the absence of A. fumigatus. One of the three results is shown.