Abstract: A suspension of inert particles is prepared in an aqueous solution, to which an antibody or an antigen and a carrier-bound antigen or antibody, respectively, are needed in any desired order. After centrifuging, the positive, weakly positive, or negative reaction can easily be recognized on the basis of a simple pattern.

Abstract: Methods and cards for detecting an antigen or antibody in a fluid sample are disclosed. The fluid sample is added to a microreaction vessel containing a slurry suspension of inert particles and a binding partner to the antigen or antibody to be determined. The fluid sample is added to the micro reaction vessel, with one of the antigen and antibody binding partners being carrier bound. The vessel contents are centrifuged, to cause the binding partners to contact each other to form an optically detectable binding complex. The location of the optically detectable complex is observed to determine the presence of the antibody.

Abstract: A method of detecting target antibodies or antigens by reaction with specific binding partners thereto is disclosed. One of the target or the binding partner is bound to a carrier, and the other is unbound. The complex between the target and the binding partner, with one being carrier-bound, forms an optically detectable binding complex. A microreaction vessel having an upper portion, a transition portion and a lower portion is utilized, wherein the upper portion has a greater diameter or width than the lower portion, and the transition portion is situated between the upper portion and the lower portion, and is funnel shaped. The microreaction vessel contains a slurry or suspension of inert particles, and unbound target or binding partner thereto. A solution of the carrier bound target or binding partner thereto is added to the vessel, which is then centrifuged to produce an optical determination of the target.