Estimation of gold-labelled macromolecules attached to cell surfaces.

A method for obtaining a semi-quantitative estimation of the amount of colloidal gold label attached to a cell surface is described. The X-ray emission, in a scanning electron microscope, from an even metal coating applied by diode sputter coating is used as an internal standard. The emission from the standard is used to correct for errors which would have arisen due to factors such as variable specimen surface topography. Examples of the semi-quantitative estimation of 10-nm gold-labelled wheat-germ agglutinin to L929 murine fibroblast cells are given.