Improved Negative Stain Electron Microscopy Procedure for Detecting Surface Detail on High Density Lipoproteins

Abstract

While conventional negative stain electron microscopy (NSEM) has been used extensively for imaging and characterizing high density lipoprotein (HDL) particles, traditional methods have not provided high-level particle surface detail. To obtain greater detail of HDL particles, we developed a modified negative staining procedure using a uranyl formate staining solution that maintains particle morphology and provides improved surface detail. The additional surface detail has allowed us to perform single-particle analysis on whole HDL particle preparations. It has also allowed us to explore interactions between HDL particle surface proteins such as Apo A with proteins that interact with Apo A such as lecithin-cholesterol acyltransferase (LCAT).