Detection of simian immunodeficiency virus in macaque lymph nodes with a SIVmac envelope probe.

A tritium-labeled DNA envelope gene probe was used to detect Simian Immunodeficiency Virus in formalin fixed lymph nodes from rhesus monkeys experimentally inoculated with SIVmac251. Cells containing SIV RNA produced strong hybridization signal and were present in small numbers in biopsy specimens and in much greater numbers in lymph nodes collected at autopsy. SIV-infected cells were morphologically identified as lymphocytes and macrophages.