Reoviral protein and RNA in cancer tissues. Routine histological analyses of tissues from patients with colorectal cancer treated with Reovirus show foci of apoptosis in the center of the malignant gland (a) and more wide spread tumor necrosis (b). (c) Shows that the signal for reoviral protein after immunohistochemistry localized to the cancer cells (small arrow) and not the stromal cells (large arrow). (d–f) Show the results of co-expression analyses for reoviral RNA, as detected by RT in situ PCR, and reoviral protein visualized with immunohistochemistry in an ovarian cancer. (e) Shows the RGB image where it is evident that most of the tumor cells contain viral RNA. Note the striking localization of the viral RNA to the tumor cell nests. (d) Shows the Nuance converted image of the reoviral protein (fluorescent red) and (f) is the Nuance image after merging the reoviral protein and reoviral RNA (fluorescent blue). Note that, although some cancer cells contain both reoviral RNA and protein (fluorescent yellow), many only contain detectable viral genome, suggesting a relatively poor rate of productive infection in this tumor.