Estimation of surface labelling on whole, critical point dried, cells by microprobe analysis in the scanning electron microscope.

A method is described whereby the relative amount of histochemical label, such as ferritin, provided it is exclusively attached to the surface of cells, can be estimated. The X-ray emission from the metal coating, deposited from a diode-sputter coating unit, is used to correct for the variations in the iron counts from the label which could occur due to changing analysis conditions.