Rapid Immunofluorescence Staining by Microwave Incubation in Patients with IgA Nephropathy

The effect of microwave incubation on the immunofluorescence staining findings in renal tissues in patients with IgA nephropathy is described. Ten patients with IgA nephropathy were examined. The renal sections were incubated with FITC-labeled rabbit anti-human IgA, IgM, IgG, or C3 antisera in a microwave oven that was operated at 2,450 MHz with an output of 500 W. There was no significant difference in the distribution of IgA or C3 deposition in the glomeruli between incubation in the microwave for 3–7 sec and 4°C overnight incubation. However, the immunofluorescence intensity of IgA after microwave incubation was less than that after incubation at 37°C for 1 min to 2 hr or 4°C overnight incubation. The intensity or distribution of IgG and IgM deposition in the glomeruli was markedly less after microwave incubation than that after incubation of 4°C overnight. We conclude that rapid immunofluorescence by microwave incubation is useful in the examination of renal biopsy specimens, especially IgA and C3 staining findings in patients with IgA nephropathy. (The J Histotechnol 13:175, 1990)