Preparation of IgG-binding membrane vesicles from the microvillar brush border of fetal rabbit yolk sac.

A one step procedure is described for the production of membrane vesicles from the endodermal microvillar brush border of the fetal rabbit yolk sac splanchnopleur. The vesicles, examined by light and electron microscopy, were shown to consist of biomolecular leaflet unit membrane, coated to varying extents with glycocalyx. By fluorescence microscopy, the homologous immunoglobulin, FITC-IgGR, has been shown to bind to the glycocalyx-coated vesicles as well as the glycocalyx-coated brush border of the intact yolk sac, whereas, the heterologous bovine immunoglobulin, FITC-IgGB, fails to bind under comparable conditions. These observations demonstrate the specificity of the receptors for the homologous IgG.