Cell surface labelling with gold colloid particulates: the use of avidin and staphylococcal protein A-coated gold in conjunction with biotin and fc-bearing ligands.

Procedures for preparing gold colloid particles stabilized with either avidin or protein A are described. Methods of using these general utility tracers for localizing biotinylated and fc bearing immunoglobulins are outlined and, as examples of the way in which these methods can be applied, procedures for identifying epidermal growth factor receptors and surface fibronectin on ovarian granulosa cells are described.