Method for determining in a sample an analyte selected from an antigen present on erythrocytes blood group or an antibody which binds to said blood group antigen, comprising treating the sample in an incubation zone of a reaction vessel a reagent containing a binding partner to the analyte, the binding partner to the analyte, in the case where the analyte is an antigen present blood group on erythrocytes, is an antibody capable of binding to blood group antigen, and the case where the analyte is an antibody binding to a blood group antigen is the antigen present on erythrocytes blood group, so that, in the incubation zone, if the sample contains the analyte, is complexed antigen present on erythrocytes and blood group antibody attached thereto, or a complex of an antigen present in erythrocytes and blood group antibody pcs or the same, as well as a complex bound complementary factors to these erythrocytes if the antibody binds supplements, further comprising separation of erythrocytes, complexed or not, with respect to unbound antibodies using a separation medium located in the reaction vessel under the incubation zone, of a higher fluid containing antibodies density but lower than the density of erythrocytes, so the erythrocytes pass through the separation medium and non-bound antibodies remain in the incubation zone, separating erythrocytes complexed erythrocytes that are not complexed to bind erythrocytes complexed in an immobilization zone of the reaction vessel, discharging erythrocytes are not complexed to a collection area reaction vessel, and detecting erythrocytes in the immobilization zone and / or collection zone, so that said immobilization zone comprises a degel matrix carrying IgM-binding antibody or antibody fragment, bound to the gel matrix by direct covalent binding or via a spacer arm.
展开▼
