RNA microarray analysis in dried blood spots

Abstract

Objectives Despite the promises and ever-decreasing costs, the genomic revolution has so far had only a marginal role in epidemiological research. This is at least partly due to lack of minimally-invasive methods of specimen collection that can be used for genomic analysis. We aimed to address this gap by testing whether a minimally-invasive method of collection through dried blood spots provides a good proxy for microarray (RNA expression) analysis in whole blood. Methods We collected venipuncture and dried blood spot samples from 19 individuals and performed whole genome expression analysis on extracted RNA using the Illumina platform. Results We found a correlation of rho = .76 and an agreement of kappa = .45 for detected genes in the two datasets (validity). We found a correlation of rho = .96 and an agreement of kappa = .72 for detected genes in the independent replicates from dried blood spots (reliability). Conclusions Genome-wise RNA expression in dried blood spots shows a moderate-to-high correlation and fair-to-good agreement with RNA expression in whole blood. If these findings are replicated in larger samples, microarray analysis in dried blood spots could be used as a minimally-invasive method to assess genomic underpinning of illness in population studies.