Silver development in microscopy and bioanalysis: a new versatile formulation for modern needs

Potentially, silver development could unify most modern demands for clean, accurately localized marker amplification in microscopy and bioanalysis. Ho wever, the existing technology leaves room for improvement in developer des ign. A new formulation has been devised which, by using principles of silve r chelation, avoids problems of self-nucleation and catalysis by light. It is made, just before use, by mixing together equal amounts of stock solutio ns containing high molarity, Tris-buffered silver nitrate and alcoholic, bu ffered pyrogallol. The two stocks are easily prepared and have very long sh elf-lives. The developer is light insensitive for up to an hour at room tem perature, so that development can proceed under ambient light conditions an d at the neutral pH most suited to biological systems. The powerful reducer in the suggested formulation should allow the detection of low concentrati ons of marker signal in a wide range of applications. (C) 1998 Chapman & Ha ll.