Fig. 1.

Comparison of GPCR expression data obtained using a GPCR-specific array and a generic cDNA array. The data were collected in two experiments, with data obtained using cDNA prepared from murine wild-type S49 lymphoma cells and that could be compared for GPCRs present on an Affymetrix Mouse Genome 430A microarray and a Taqman GeneSignature array. The 32 GPCRs highly expressed (>log2⁶) on the Affymetrix array show a positive correlation (R² = 0.37) between the two arrays. GPCRs expressed at lower levels (<log2⁶) show numerous false-positive and false-negative results in the detection of GPCRs by the Affymetrix array compared with the GPCR array (R² = 0.01). ΔCT, cycle threshold relative to the mRNA used to normalize expression of each GPCR; GCRMA, guanine cytosine robust multiarray analysis.