House keeping gene analysis - carcinoids and normal mucosa

Accurate and reproducible quantitation of target genes depends on correct normalization. Historically, genes with variable tissue transcription e.g. GAPDH, have been used as normalization factors which is problematic, particularly in clinical samples which often are derived from different tissue sources. Using a large-scale gene database (GeneChip (Affymetrix U133A) dataset of 36 gastrointestinal tumors and normal tissues), we identified 8 candidate reference genes that were highly expressed with low variability and established expression levels by real-time RT-PCR in an independent set of GI tissue samples (n=42). Keywords: house-keeping, intestine, carcinoid (GeneChip (Affymetrix U133A) dataset of 36 gastrointestinal tumors and Affymetrix protocol: http://keck.med.yale.edu/affymetrix/analysis.htm