Validation of microarray observed
. cenocepacia gene expression by semi-quantitative PCR. The results of semi-quantitative RT-PCR on cDNA derived from sputum-grown B. cenocepacia (panel A) and from cells grown under control conditions (panel B) are shown. The products amplified after set numbers of PCR cycles (labelled below each panel) are shown for the following genes: 1, ferric reductase transmembrane gene (BCAL0270; up-regulated in sputum); 2, conserved hypothetical gene (BCAL1165; down-regulated in sputum); and 3, phaC (BCAL1861; control gene without altered expression). Molecular size markers are shown on the left hand side of each gel and the relevant size fragments indicated in bp.