Labeled cRNAs were purified using the Qiagen kit (according to manufacturer’s instructions) and then fragmented to approximately 50 to 200 bp by heating at 94°C for

35 min. Fifteen micrograms (15 μg) was then hybridized to a Chlamydia whole genome Affymetrix Custom array. The array is an Affymetrix oligonucleotide array format of 1800 features, covering the full C. trachomatis genome (875 genes) and containing 8-11 oligonucleotides per target gene, each designed for optimal hybridization to C. trachomatis and/or C. pneumoniae and screened for non-specific hybridization against CYC202 solubility dmso the full human and mouse genomes. After hybridization and subsequent washing using the Affymetrix Fluidics station 400, the bound cRNAs were stained with streptavidin phycoerythrin,

and the signal amplified with a fluorescent-tagged antibody to streptavidin (Performed by AGRF). Fluorescence was measured using the Affymetrix scanner and the results analysed using GeneChip 1.4 analysis software, resulting in the detection of 1175 genes. A total of 16 chlamydial arrays were analysed with the 4 culture conditions (no hormone, E, P, E+P) × four replicates. The entire microarray data recorded in Gene Expression Omnibus (GEO) database with accession number GSE24119. Quantitative PS-341 in vitro RT-PCR find more Quantitative Real-Time PCR was used to validate the microarray data for 20 selected target genes. Each primer pair was used to generate amplicon standards by amplifying previously generated C. trachomatis cDNA. cDNA generation was performed using the SuperScript® III Reverse Transcriptase technique (Invitrogen, Aldol condensation Carlsbad, CA, USA). One μg of template was added to the PCR mixture containing 0.15 μM of gene specific forward and reverse primers, 1 × SYBR Green

reaction mastermix, before being made up to a final volume of 25 μL with distilled water. The mix is optimized for SYBR Green reactions and contains SYBR Green I dye, AmpliTaq DNA Polymerase, dNTPs and optimized buffer components. Cycling parameters for all reactions were as follows: denaturation at 95°C for 10 min; 40 cycles of denaturation at 95°C for 15 sec and 1 min of annealing and extension at 60°C; and melting curve analysis from 60°C to 95°C. The Rotor-Gene 6000 fast real-time PCR system (Corbett) was used for relative quantification of cDNA copies for the 20 selected genes and an internal reference gene (16S rRNA) was used in all experiments. Quantitation was carried out by using a standard curve based on serial dilutions of the amplicon standards covering 6 logs. Real-time PCR templates for each gene of interest included fresh dilutions of the amplicon standards, 8 cDNA samples (2 × 4 samples per experiment) and distilled water as a negative control. All reactions were performed in triplicate. Reaction tube mastermixes were prepared as per the preparation of amplicon standards described above.