The LI Silver (LIS) Enhancement Kit is a convenient, light-insensitive silver enhancement system for use with our colloidal gold and NANOGOLD reagents. Gold particles in the presence of silver (I) ions and a reducing agent act as catalysts to reduce the silver (I) ions to metallic silver. The metallic silver is deposited onto the gold, enlarging the particles to between 30 and 100 nm in diameter. Tissue or blots stained with colloidal gold are “developed” by this autometallographic procedure to give black staining that can be seen in the light microscope. The LI Silver Enhancement Kit is prepared for Molecular Probes by Nanoprobes, Inc.