The Ptac-csrB1 expression cassette was removed from pGEM via SalI-SphI digestion, and ligated into pVSV104, which had been digested in the same way, to create pJW4. The integrity of pJW3 and pJW4 were confirmed by sequencing. pJW3 or pJW4 were used to transform E. coli DH5αλpir and were subsequently introduced into V. fischeri ES114 or PMF8 via tri-parental conjugation using the helper strain E. coli (pEVS104) (Stabb & Ruby, 2002). To introduce pJW3 or pJW4 (KmR) into PMF8 (KmR), Ap (50 μg mL−1) was added to the selection plates to select against

the E. coli donor with no impact on V. fischeri. Presence of the vector in PMF8 was verified by plasmid purification followed by PCR to amplify the expression cassette. pVSV104-based vectors are known to be stably maintained in V. fischeri without antibiotic selection (Dunn et al., 2006). To confirm this, plasmid stability Everolimus purchase was examined by growing KmR strains without selection for 3 days followed by plasmid isolation and PCR screening. Two methods of experimental design were employed in this Selleckchem Idasanutlin study to enable a side-by-side comparison of the approaches. All experiments were performed using standard laboratory set ups (at least

two independent experiments assayed in triplicate). In addition, factorial design was simultaneously used to test the efficacy of this approach for laboratory-based studies (where it has not been commonly adopted). The design and analysis of the factorial experiments were carried out using the statistical application program Design Expert from Stat-Ease (Minneapolis, MN). For all experiments, data collection was carried out in random order to minimize systematic error from uncontrolled factors such

as drift in measurement instruments. The anova analysis allows identification of statistically significant model terms, based on P-values, which will be included in the multiple variable regression analysis of the response variables (luminescence Carnitine palmitoyltransferase II and transcript levels). Vibrio fischeri strains were grown to mid-exponential phase (OD600 nm 0.6). Once this OD was reached, 200 μL samples were taken and added in triplicate to a white 96-well microtiter plate for luminescence readings. Data were collected on a Beckman-Coulter LD400 luminometer, with an integration time of 1 s per well, and with the photometer wavelength set to 492 nm. Vibrio fischeri was grown as described earlier, and 500 μL cell samples were collected. Qiagen RNAprotect Bacteria Reagent was used to stabilize RNA in cell pellets prior to storage at −70 °C. Total RNA was extracted using a Qiagen RNeasy mini kit and stored at −70 °C. RNA was analyzed for integrity and concentration using a Bio-Rad Bioanalyzer, and converted to cDNA using an Applied Biosystems High-Capacity cDNA Reverse Transcription kit. cDNA samples were stored at −20 °C until use as templates in an Applied Biosystems 7300 Real-Time PCR system.