Patent ID: 7618784

Claim:
A method to determine the activity of phospholipid transfer protein (PLTP) in a sample, which method comprises, (a) providing an initial reaction mixture, maintained in a buffer, wherein the initial reaction mixture has a physiological salt concentration having a density of about 1.006 g/ml, and the initial reaction mixture comprises: (i) the sample comprising PLTP, and (ii) a donor particle comprising a labeled PLTP substrate and an aqueous core; (b) adding an acceptor emulsion to the initial reaction mixture, wherein the acceptor emulsion comprises an acceptor to which the substrate may be transferred; (c) adding a salt solution to the initial reaction mixture making the initial reaction mixture a final reaction mixture, wherein the salt solution added has a density greater than about 1.006 g/ml, and wherein the density of the final reaction mixture is greater than about 1.006 and less than about 1.2 g/ml, and wherein addition of the salt solution to the initial reaction mixture causes the donor particle comprising the labeled PLTP substrate to be disrupted, allowing PLTP to transfer the labeled PLTP substrate to the acceptor; and (d) measuring the amount of labeled PLTP substrate transferred to the acceptor, thus determining the PLTP activity of the sample.