Method and apparatus useful for detecting bloodgroup antigens and antibodies

A method for detecting a bloodgroup antigen on erythrocytes, comprising the steps of:

• obtaining a sample of erythrocytes to be tested;
• adding said sample to a reaction tube, said tube having a lengthwise axis and containing a reaction medium, said reaction medium comprising a plurality of particles which have immunoglobulin-binding ligands selected from the group consisting of Protein A, Protein G, Protein A/G and a universal kappa light chain binding protein coupled to the surface of said particles, a bridging antibody coupled to said ligand and antibodies specific for said bloodgroup antigen coupled to said bridging antibody on said particles;
• centrifuging said reaction tube for a time sufficient to pellet to the bottom of said reaction tube erythrocytes that do not attach to said antibodies coupled to said bridging antibodies that are coupled to said ligands on said particles;
• detecting attachment of said erythrocytes to said particles or lack thereof;
• and
• correlating attachment with the presence of said bloodgroup antigen.

A method for detecting a blood cell antigen in blood typing, comprising the steps of:

• obtaining a sample of erythrocytes to be tested;
• incubating said erythrocytes in a reaction tube with a preparation of antibodies specific for a known blood cell antigen under conditions and for a time sufficient to bind said antibodies to said antigens if said antigens are present, said tube having a lengthwise axis and also containing a plurality of particles which have immunoglobulin-binding ligands selected from the group consisting of Protein A, Protein G, Protein A/G and a universal kappa light chain binding protein coupled to the surface of said particles;
• centrifuging said reaction tube for a time sufficient to pellet to the bottom of said reaction tube erythrocytes that do not attach to said ligand on said particles;
• and
• correlating attachment of said erythrocytes to said particles with the presence of said antigen on said erythrocytes.

A method for detecting blood serum antibodies specific for blood cell antigens, comprising the steps of:

• obtaining a sample of erythrocytes having known antigens on the surface thereof;
• obtaining a sample of blood serum to be tested for antibodies against said antigen;
• incubating said erythrocytes and said serum in a reaction tube under conditions and for a time sufficient for said antibodies to bind to said antigens on said erythrocytes if said antibodies are present, said tube having a lengthwise axis and also containing a plurality of particles having a ligand comprising an immunoglobulin-binding protein selected from the group consisting of Protein A, Protein G, Protein A/G and a universal kappa light chain binding protein coupled to the surface of said particles;
• centrifuging said reaction tube for a time sufficient to pellet to the bottom of said reaction tube erythrocytes that do not attach to said ligand on said particles;
• and
• correlating attachment of said erythrocytes to said particles with the presence of said antibodies.

A method for detecting blood serum antibodies specific for blood cell antigens, comprising the steps of:

• obtaining a sample of erythrocytes having known antigens on the surface thereof;
• obtaining a sample of blood serum to be tested for antibodies against said antigens;
• incubating for about 10 minutes at about 37.degree. C. said erythrocytes and said serum in a reaction tube, said tube having a lengthwise axis and containing a plurality of particles having Protein G coupled to the surface of each of said particles;
• centrifuging said reaction tube for about 15 seconds at from about 900-1000 g, then for about 30 seconds at from about 500 g, and then for about 45 seconds at from about 900-1000 g using a centrifuge adapted so that a centrifugal force generated by said centrifuge acts along the axis of said reaction tube;
• detecting attachment of said erythrocytes to said Protein G on said particles or lack thereof;
• and
• correlating attachment with the presence of said antibodies tested for.

An apparatus useful for detecting bloodgroup antigens and antibodies, comprising:

• a plurality of reaction tubes being spaced apart and coupled together to form a single unit array of said reaction tubes, said array being adapted for use in a centrifuge;
• each of said reaction tubes having:
• an upper longitudinal region having a substantially rectangular cross-section of preselected width, forming a reaction well adapted to receive reagents and erythrocytes;
• a lower longitudinal region having a substantially circular cross-section of a preselected diameter less than said preselected width, forming a tube portion containing a column of immunoreactive particles having a ligand selected from the group consisting of Protein A, Protein G, Protein A/G or a universal kappa light chain binding protein coupled to the surface of said particles;
• and
• an intermediate longitudinal region having a diameter varying between said preselected width and said preselected diameter, said intermediate longitudinal region providing fluid communication between said upper and lower longitudinal regions.