Patent ID: 7772007

Claim:
An assay device for the direct measurement of low-density lipoproteins (LDL) in a blood fluid sample also containing high density lipoproteins (HDL), very low density lipoproteins (VLDL), and/or chylomicrons, the device comprising: (a) a sample loading area; (b) a plurality of porous elements through which said blood fluid sample can flow in sequence by capillary action and/or gravity, wherein adjacent elements are or can be placed in fluid communication with each other, said plurality comprising: (1) a VLDL/chylomicron precipitation element, containing reagents effective to selectively precipitate VLDL and chylomicrons in said sample, and composed of a material effective to remove such precipitated VLDL and chylomicrons from said sample; (2) an antibody element, containing an antibody effective to specifically bind HDL, thereby forming an HDL-antibody complex; (3) a capture zone, wherein said HDL-antibody complex can be bound and thereby removed from said fluid sample; and (4) an LDL test pad, downstream of said capture zone and said precipitation element, in which LDL concentration can be assayed, wherein said precipitation element is upstream of said antibody element or downstream of said capture zone; and (c) a mounting element effective to adjust the relative positions of said porous elements in such a way as to bring elements into or out of fluid communication with each other.