This is an overview of our approach for using the transgenic C. elegans system to understand the molecular basis of beta-amyloid toxicity. Central to this approach is the global determination of gene expression using DNA microarray hybridization. We are currently pursuing microarray analysis in collaboration with Stuart Kim (Stanford University). To date we have generated data from four amyloid/control comparisons using microarrays containing probes for ~12,000 C. elegans genes.