In vitro cDNA libraries from scrapie-infected and non-infected murine neuroblastoma cell lines were screened with cDNA probes derived by subtractive hybridization from scrapie-infected and uninfected cells to identify genes with altered expression associated with scrapie infection. Eleven independent recombinant clones, whose expression was either increased or decreased in scrapie-infected cells, were identified. Expression of these genes was also analyzed in a panel of scrapie-infected and non-infected cell lines. Five genes had altered mRNA expression in most scrapie-infected neuroblastoma cell clones compared to non-infected clones. These genes were chromogranin B, intracisternal-A particle envelope, ornithine decarboxylase antizyme, heat shock protein 70 and one unidentified gene. None of these alterations in gene expression was uniquely scrapie-specific; however, the skewed association of increased expression with scrapie infection suggested that a causal relationship might exist between scrapie infection and altered expression of these genes in mouse neuroblastoma cells in vitro.