MOLECULAR RESOLUTION ATOMIC-FORCE MICROSCOPY OF SOLUBLE-PROTEINS IN SOLUTION

We introduce a simple specimen preparatory method for atomic force mic roscopy of soluble proteins in aqueous solutions. It is demonstrated t hat the mica surface is suitable for direct adsorption of macromolecul es that are sufficiently stable to withstand the disturbance of the pr obe for reproducible imaging at high resolution. It is also shown that the main problem impeding successful imaging is the excessive adsorpt ion of macromolecules, as loosely bound macromolecules readily stick t o the tip and produce various imaging artifacts.