ANALYSIS OF IMMUNOLABELED CELLS BY ATOMIC-FORCE MICROSCOPY, OPTICAL MICROSCOPY, AND FLOW-CYTOMETRY

In this study we investigated the applicability of the (silver-enhance d) immunogold labeling method for atomic force microscopy. Human lymph ocytes were labeled with anti-CD3 conjugated to fluorescein isothiocya nate and a secondary antibody (goat anti-mouse) linked with 1- or 30-n m colloidal gold particles. Silver enhancement was applied on these la beled cells to increase the size of the labels. In a setup combining a n inverted optical microscope and a stand-alone atomic force microscop e, a direct correlation was made between the force and the fluorescent images. Additionally, we performed how cytometric analysis. From the results we conclude that immunogold labeling using small labels (1 nm) in combination with silver enhancement (30 min) proves to be a reliab le method for high-resolution cell surface antigen detection in atomic force microscopy. (C) 1994 Academic Press, Inc.