Abstract: Methods are provided for monitoring treatment of a subject using heparin therapy or a ligand, such as an CD20 or CD52 antibody, that binds to a cellular marker and to which the subject may develop masking reactions or auto-antibodies that inhibit evaluation of treatment. The methods involve adding to a single container a sample containing cells that express the cellular target with (i) a soluble ligand that binds the cellular target, (ii) a soluble ligand that binds the soluble analyte or a competing soluble analyte; and (iii) a capture medium that binds directly to the soluble analyte, indirectly to the soluble analyte, or to the soluble ligand that binds to the soluble analyte. Complexes formed in the container by interaction of these components are substantially simultaneously analyzed and quantitated without physically separating the complexes. Kits for performing the assays are also provided.

Abstract: A method for evaluating a biological sample containing at least one cell type bearing at least one cellular target and at least one soluble analyte, involves adding to a single container the sample with (i) at least one soluble ligand that binds the cellular target, (ii) either at least one soluble ligand that binds the soluble analyte or at least one competing soluble analyte; and (iii) a solid phase capture medium that binds directly to the soluble analyte, indirectly to the soluble analyte, or to the soluble ligand that binds to the soluble analyte. Various complexes involving the capture medium and soluble analyte, the capture medium and the soluble ligand, and/or the cellular target and a soluble ligand are simultaneously analyzed without physically separating the complexes.