Colloidal gold is a suspension (colloid) of submicrometer-sized particles of gold in a liquid medium. Suspension of gold colloid in fluid results in a vivid red or yellow appearance depending on the size of the gold particles used. The interesting properties of gold and silver colloids have been studied since ancient times and there is currently significant interest in utilizing colloidal gold nanoparticles in cancer detection and Alzheimer’s therapies; modern biological researchers however are mostly interested in their unique molecular binding, recognition, carrier and tagging properties. Fitzgerald Industries offers a large range of colloidal gold suspensions for sale; our highly pure, highly stable suspensions are available in multiple nanometre sizes (250 nm, 200 nm, 150 nm, 100 nm, 80 nm, 60 nm, 50 nm, 40 nm, 20 nm, 15 nm, 10 nm, 5 nm and 2 nm). As well as pure gold colloids we also supply gold Colloid conjugated antibodies such as HBsAg antibody (Gold Colloid), hCG beta antibody (Gold Colloid), THC antibody (Gold Colloid) and many more. Commonly used gold colloid conjugated research proteins such as Streptavidin, Protein A, Protein G as well as a selection gold colloid conjugated immunoglobulins and Gold staining Kits are also available. Fitzgerald also offers highly pure silver colloid (20 nm) for sale as well as a Silver Enhancing Kit, useful for amplifying the signal response in assays involving silver and gold colloids. Our range of gold and silver colloids are available to buy in bulk quantities or individual titres and our catalog is continuously updated with new research products so please do not hesitate to contact us with your specific requirements.