Patent ID: 7262019

Claim:
A method for detecting an antibody that binds to a Bacillus anthracis antigen in a sample, comprising: providing a first component comprising biotin linked through a polyethylene glycol, to albumin; providing a second component comprising a biotin-binding moiety conjugated to said antigen; providing a third component comprising said antigen conjugated to a label; contacting the first component with a solid phase so as to immobilize the first component; contacting a sample suspected of comprising said antibody with the second and third components such that a mixture is formed comprising: a triple immune complex in which the antibody, if present in the sample, binds to the antigen of each of the second and third components; and, uncomplexed third component; contacting the mixture with the immobilized first component so as to immobilize the triple immune complex but not uncomplexed third component, wherein triple immune complex is immobilized by the binding between the biotin of the first component to the biotin-binding moiety of the second component; separating the mixture comprising uncomplexed third component from the solid phase; and detecting whether the label is associated with the solid phase, wherein the detection of the label indicates the presence of the triple immune complex in the mixture and therefore of the antibody in the sample.