| abstract |
A method, apparatus and system for conducting assays of one or more substances of a fluid sample, which assays are based upon biospecific affinity reactions and comprise the binding thereof to receptors immobilized to a carrier material to form immobilized complexes, and the determination thereof. In the method the carrier material is provided in a column and divided into at least one test portion, to which one or more receptors for the substance or substances to be determined are bound, and at least one reference portion, and, to effect said assay reactions, the necessary analytical solutions are sequentially, and when required with intervening incubation, aspirated into the column, a subsequent addition of solution displacing the preceding one, and said determination is then conducted directly on the column by a comparative visual or instrumental, such as a fluorimetric or colorimetric, determination of said test and reference portions. An apparatus for carrying out the method comprises a column member (9) having an inlet opening (11) at one end thereof and containing a carrier material, said carrier material being divided into at least one test portion, to which one or more receptors for the substance or substances to be determined are bound, and at least one reference portion, adapted to provide a reference in said determination; and an aspirator and liquid collecting device (3, 4) connected or connectable to the other end of said column member (9) and comprising a hollow member (3) having an axially movable plunger (3a), at least part of said column member (9) being transparent to permit a comparative visual or instrumental determination of the material in said test and reference portions directly on the column. A system for conducting such assays comprises said apparatus in combination with measuring means adapted to the column member thereof for performing said comparative determination of said test and reference portions. |