A retrograde double-labeling technique for light microscopy A combination of axonal transport of cholera toxin B-subunit and a gold-lectin conjugate

A light microscopical, non-fluorescent, retrograde double-labeling technique is described. Cholera toxin B-subunit (CTb) and a conjugate of wheatgerm agglutinin and bovine serum albumin coupled to 10 nm gold particles (gold-lectin) are both excellent retrograde tracers and, when visualized by means of immunohistochemistry and silver intensification, respectively, may be readily identified within the same cell. This light microscopical retrograde double-labeling technique is illustrated in rat with experiments designed to investigate the collat