The preparation and use of antibody microprobes

A new method of detecting release of neuropeptides in the central nervous system is described. Glass micropipettes are treated with gamma-aminopropyltriethoxysilane resulting in a fine outer coating of a siloxane polymer containing free amino groups. Glutaraldehyde is then used to covalently couple protein A which in turn binds antibodies to a particular peptide. Following use in the central nervous system, microprobes are incubated in a radiolabelled form of the peptide being studied and release is detected on autoradiographs as localized zones of inhibition of binding of the labelled peptide. The spatial resolution of the method is at least 100 micron. Necessary tests of the validity of the technique are also described.