Abstract
A variety of highly sensitive laboratory techniques is now available for the detection and localization of infectious agents in the placenta. This communication discusses, the role of immunohistochemistry, immunofluorescence, in situ nucleic acid hybridization, and polymerase chain reaction for infectious disease diagnosis in formalinfixed placental tissues. These techniques, as well as other sophisticated molecular methods currently in development, will greatly facilitate characterizing the role of infectious agents in a variety of perinatal and pediatric conditions, including birth defects, intrauterine growth retardation, and stillbirth.