The method for converting biocytin preparations of brain sections fills a gap in the application of confocal laser-scanning microscopy. Both neuronal and non-neuronal structures are converted. The background remains free of staining. The protocol can be applied to old and already existing biocytin-(diaminobenzidine)-nickel preparations which are then made accessible to evaluation with the laser-scanning microscope by the substitution of nickel with silver-gold. Sodium thiosulphate is used to remove the unbound silver. The reflection image of the laser-scanning microscopy provides more information than the transmission image.