We describe the fluorescent labeling of gibbsite particles. Gibbsite particles are first stabilized with polyvinyl pyrrolidone. Subsequently the particles are covered with a silica layer in which a fluorescent dye is incorporated. Both fluorescein and rhodamine dyes have been used. The fluorescent labeling is applicable to gibbsite particles Of Various sizes. Particles are transferred to dimethyl formamide by vaccuum distillation after dialysis. These particles are used for confocal scanning laser microscopy and confocal fluorescence-recovery after photobleaching. (c) 2005 Elsevier Inc. All rights reserved.