A new microarray platform, AuroGen™, has been developed, which performs gene expression analysis without reverse transcription and chemical modification of the target mRNA for detection. The AuroGen™ hybridization signal results from the precipitation of nanogold particles on the hybridized array spots due to the electrostatic attraction of the cationic gold particles and the anionic phosphate groups in the target DNA backbone. In contrast to the conventional fluorescent detection, this nanoparticle-based detection platform eliminates the target labeling procedure, such that target mRNA can be analyzed in its native, non-modified state. The visualization and quantification of hybridization signals is accomplished with a flatbed scanner instead of a confocal laser scanner, which greatly simplifies the process and reduces the cost. Performance of the AuroGen platform was investigated in experiments in which a known quantity of target DNA was spiked into total RNA from human kidney. The AuroGen™ array system is able to detect less than 1 pg of DNA molecules captured on a microarray. Intra-array and cross-array reproducibility is adequate for detection of less than a 2-fold change in gene expression across two separate experiments. The AuroGen™ microarray platform provides a simple and cost effective solution for different applications, which require DNA mapping and differential gene expression analysis in low and high density multiplexing format.

[Proc Amer Assoc Cancer Res, Volume 46, 2005]