Disclosed is a method of detecting reactive antibody in the serum of a subject including the steps of: Contacting a sample of the serum with a suspension of cells modified to incorporate a peptide-lipid construct of the structure (L-S-)iF(-S-L)j to provide a mixture Incubating the mixture for a time and at a temperature sufficient to allow agglutination and Determining the degree of agglutination of the cells in the mixture where: F is a peptide comprising an epitope for the reactive antibody S is a spacer covalently linking F to L and L is a lipid selected from the group consisting of diacyl- and dialkyl-glycerolipids, including glycerophospholipids and i and j are independently 0 or 1.
