The effect of microwave-generated energy for the demonstration of immunoglobulins in periodate lysine paraformaldehyde dichromate fixed paraffin sections of human reactive tonsil using the immunogold silver staining technique has been evaluated. Results of the study show that microwave stimulation permits incubation times of both the primary antibody and the immunogold reagent to be greatly reduced. Specific staining of equal intensity to that produced using the longer standard procedure together with minimal background staining is achieved.