96-well nephelometric assay to detect calcification propensity of serum samples
The precipitation of Ca2+ and phosphate results in calcium phosphate that is used for building up bone and teeth. Disregulation of this strictly regulated process may result in cardiovascular diseases. Here, we present a novel assay to determine the intrinsic ability of serum to inhibit calcification. It relies on the formation of small colloidal protein-mineral complexes, so-called primary calciprotein particles (CPP). These are converted into secondary CPPs and the time it takes for conversion reflects the inhibitory calcification propensity of the serum. Secondary CPPs differ from primary CPPs in regard to particle diameter and shape which can be detected by measuring light scattering.
This nephelometric assay was measured on BMG LABTECH's Nephelostar® Plus in sera of transgenic mice with different propensities to inhibit calcification. These differences were mirrored by differing conversion times of primary to secondary CPPs. Furthermore, different conversion times were determined for hemodialysis patients that have an increased risk in for calcifications.