Figure 2. Binding of the patient's IgG to Purkinje cells is inhibited by pretreatment of rat tissue with anti-VGCC antibodies, confirming specificity of the patient's antibody response.
Adult rat tissue was fixed, sectioned, and treated with an antigen retrieval system before blocking for 1 hour with serial concentrations of commercially obtained rabbit anti-VGCC antibodies directed against the α1A subunit of the VGCC receptor before being exposed to a 1:200 dilution of patient serum for 24 hours. Tissue was then labeled with Cy5-conjugated donkey anti-human IgG to detect the patient's antibodies and fluorescein isothiocyanate–conjugated anti-rabbit IgG to detect the commercial anti-VGCC antibody. Pretreatment with commercial anti-VGCC antibody inhibited binding of the patient's IgG to Purkinje cells in a dose-dependent manner, confirming the specificity of the patient's antibody for the VGCC. Scale bars = 20 μm. IgG = immunoglobulin G; VGCC = voltage-gated calcium channel.