METHOD OF PRODUCING A REAGENT CONTAINING A NARROW DISTRIBUTION OF COLLOIDAL PARTICLES OF A SELECTED SIZE AND THE USE THEREOF

摘要

A method to produce a reagent containing a narrowdistribution of metal sol particles of a selected size for use asimmunoassay reagents or as cell markers or labels for microscopictechniques. Applicants' novel colloidal seeded metal sol processincludes: preparing gold nuclei or seed using a strong reducingagent in the presence of a stabilizing agent selected so thatneither agent will appreciably affect the subsequent growth ofthe seed produced; preparing metal sol particles of differentsizes using seed prepared in accordance with Applicants' methodand hydroxylamine or sodium citrate as the reducing agent;inactivating hydroxylamine and its reaction byproducts whenhydroxylamine is the reducing agent: coating the particles with aselected material; and using delipidated milk as a post-coater.