Method and card for detecting antigens and/or antibodies

A method of detecting an antibody in a fluid sample by an indirect Coombs test, said method comprising:

• providing a microreaction vessel containing a slurry or suspension of inert particles and Coombs serum;
• adding about 10-150 .mu.l of at least one fluid sample to the vessel;
• adding to the vessel a carrier bound antigen which specifically binds to the antibody to form a binding complex;
• incubating a mixture of the fluid sample and the carrier-bound antigen to form a binding complex between the carrier-bound antigen and the antibody;

A method of detecting target antibodies or antigens by reaction with specific binding partners thereto, wherein one of either the target or the binding partner is bound to a carrier and the other is unbound, a complex of the carrier-bound target and the binding partner, or of the target and the carrier-bound binding partner, forming an agglutinate which is optically detectable, said method comprising:

• providing a microreaction vessel, sized to receive at least one fluid sample of about 10-150 .mu.l, containing a slurry or suspension of inert particles and the known unbound target or binding partner thereto, said vessel being substantially transparent and having an upper portion and a lower portion, said upper portion having a greater diameter or width than the lower portion, with a transition portion situated between the upper portion and the lower portion, said upper portion having a sealed, openable upper sample receiving end said lower portion having a closed lower end;
• adding about 10-50 .mu.l of a solution containing the carrier-bound target or binding partner to the vessel to form a target-binding partner complex which is carrier-bound and optically detectable;
• centrifuging the vessel;
• and
• observing the location of the carrier-bound complex to determine the presence of the target antibody or antigen to be detected, with a strongly positive reaction being indicated by a complex lying upon or in a top portion of a layer of the inert particles, a weakly positive reaction being indicated by a complex located within a lower portion of the layer of inert particles, and a negative reaction being indicated by the absence of a complex, with the carrier-bound target or carrier-bound binding partner lying beneath the inert particles.

A method of detecting analyte antibodies or antigens in a fluid sample by reaction with known antigen or antibody, respectively, binding partners exhibiting specific binding affinity thereto, wherein either the analyte or known antigens or antibodies are bound to a carrier, the complex of the carrier-bound antigen and the analyte antibody, or of the carrier-bound antibody and the analyte antigen, forming an agglutinate which is optically detectable, said method comprising:

• providing a microreaction vessel containing a slurry or suspension of inert particles;
• centrifuging the fluid sample and the binding partner in said vessel in the presence of the inert particles;
• and
• determining the presence of analyte antibodies or antigens by observing the location of any agglutinate, with a strongly positive reaction being indicated by an antigen-antibody complex lying upon a top portion of a layer of the inert particles, a weakly positive reaction being indicated by an antigen-antibody complex located within a lower portion of the layer of inert particles, and a negative reaction being indicated by the absence of an antigen-antibody complex with the carrier-bound antigen or antibody lying beneath the inert particles;
• wherein the vessel is an elongated vessel having an upper open end and a lower closed end, with the vessel being transparent and having an upper sample receiving portion, a funnel-shaped transition portion, and a lower portion which contains the inert particles, the upper portion having a greater diameter or width than the lower portion with the transition portion being situated thereinbetween, said vessel being sized to receive a body fluid sample of about 10-150 .mu.l.