A novel vesicular assay to study factors affecting cholesterol crystallization in vitro

We present an assay to study cholesterol crystallization that is fast, facile, and highly reproducible. Cholesterol crystallization from metastable vesicles was induced upon addition of bile salts and depended on the hydrophobicity of the bile salt used and the cholesterol-to-phospholipid ratio of the vesicles. Bile salt-induced crystallization was stimulated upon addition of Con A-binding glycoproteins (CABGs), comparable to the results of the same CABGs in a crystal growth assay. The onset time and total measuring time, however, were much shorter. This assay might, moreover, provide a tool to study the mechanism of cholesterol crystallization in more detail.