IgG and IgA antigens in human renal basement membranes

Cryostat sections of fresh human kidney studied by immunofluorescence were negative for IgG, IgA, IgM, Fc and Fab fragments of IgG, and kappa and lambda light chains. All of these conjugates except anti-IgM stained glomerular basement membranes and several other connective tissues if the cryostat sections were washed in phosphate-buffered saline (PBS) before being studied. Staining was inhibited by blocking reactions as well as by fixation before washing in PBS or by washing in non-ionized or hypotonic solutions. Results of several other aspects of this reaction are also reported.