FIG. 2.

Negative-stain electron micrograph of in vitro assembly products. (A) CA. (B) ΔMA-CA. Protein solutions (3 mg/ml) were dialyzed overnight against 50 mM Tris HCl (pH 8.0) containing 1 M NaCl, stained with 1% uranyl acetate, and analyzed by electron microscopy. To immobilize ΔMA-CA-derived particles, the grid had been coated with purified CA-specific antibodies. No difference in size or morphology of particles was observed when grids without antibodies were used instead. Bar, 100 nm.