Use of hybrid antibody with anti-gamma-G and anti-ferritin specificities in locating cell surface antigens by electron microscopy.

Hybrid antibody [F(ab')(2)] with dual specificity for mouse gammaG and ferritin was prepared from the corresponding rabbit antisera, providing a precise reagent for locating mouse gammaG on cell surfaces. Viable cells were exposed successively to (a) mouse antibody to a cell surface antigen, (b) the rabbit hybrid antibody, and (c) ferritin, before preparation for electron microscopy. This method of See PDF for Structure. labeling is sensitive and specific and clearly lends itself to the introduction of visual markers other than ferritin. Other advantages are uniformity of labeling, ease of purification of the reagent, and circumvention of the many drawbacks arising from coupling ferritin to antibody chemically.