Toxicogenomic analyses of Ruditapes philippinarum by DNA microarray: new tools for anthropogenic impact assessment on the Venice Lagoon.

A manila clam oligo microarray platform (GPL10900) was used to profile gene expression in digestive gland of R. philippinarum sampled in four seasons in 4 different areas of Venice Lagoon. For each tissue, total RNA was extracted from four (4) independent biological replicates of digestive gland, each consisting of tissue pools of five (5) animals. In this study, we analyzed 64 samples (pools of 5 digestive gland). Gene expression profiling was performed using the Agilent-027304 Ruditapes philippinarum Oligo Microarray platform (GPL10900) based on single-colour detection (Cyanine-3 only). Microarrays were scanned with Agilent scanner G2565BA (barcode on the left, DNA on the back surface, scanned through the glass) at a resolution of 5 microns; all slides were scanned twice at two different sensitivity settings (XDRHi 100% and XDRLo 10%); the scanner software created a unique ID for each pair of XDR scans and saved it to both scan image files. Feature Extraction (FE) 9.5 used XDR ID to link the pairs of scans together automatically when extracting data. The signal left after all the FE processing steps have been completed is ProcessedSignal that contains the Multiplicatively Detrended, Background-Subtracted Signal.