FIG. 4.

RT-PCR analysis of abundance of transcripts in P. aeruginosa PAO1 grown planktonically and as a biofilm. RT-PCR analysis of ccoO (PA1553), PA4101, mexH (PA4206), and crc expression in P. aeruginosa PAO1 grown planktonically (P) and as a biofilm (B). Amplification of the ccoO transcript resulted in a 270-bp PCR product and amplification of the PA4101 and PA4208 transcripts in 320- and 280-bp PCR products, respectively. The PCR product for the crc transcript was 330 bp. For the determination of ccoO transcript abundance in biofilms, cDNA from 4-day-old biofilms was used; for PA4101 and PA4208 transcript abundance in biofilms, cDNA obtained from 6-day-old biofilms (maturation-2 stage) was used. The oligonucleotide pairs used for the RT-PCR analysis are listed in Material and Methods. M, DNA marker.