Abstract: The current invention is directed to an antibody comprising at least four binding sites specifically binding to an immunoglobulin Fc-region of the human IgG1 subclass comprising one, two, three or four amino acid changes compared to a wild-type Fc-region of the human IgG1 subclass for use as positive control and calibration standard in an immunoassay for the detection and quantification of anti-drug antibodies against said one, two, three or four amino acid changes in the Fc-region of the drug antibody.

Abstract: The invention provides anti-variant Fc-region antibodies which specifically bind to an antibody that has the mutation P329G or the mutations P329G/L234A/L235A or the mutations 1253A/H310A/H435A in the Fc-region, and methods of using the same.

Abstract: Herein is reported an anti-drug antibody immunoassay for the determination of the presence of an anti-drug antibody against an effector function suppressed human or humanized drug antibody in a sample comprising the incubation of a sample comprising mammalian blood serum with full length human Fcgamma receptor I or an Fc-region binding fragment thereof so that a complex between the anti-drug antibody against the effector function suppressed human or humanized drug antibody present in the sample and the human Fcgamma receptor I or the Fc-region binding fragment thereof forms, whereby the full length human Fcgamma receptor I or the Fc-region binding fragment thereof is conjugated to a detectable label, and the determination of the formed complex by the detectable label.

Abstract: The invention provides anti-variant Fc-region antibodies which specifically bind to an antibody that has the mutation P329G or the mutations P329G/L234A/L235A or the mutations 1253A/H310A/H435A in the Fc-region, and methods of using the same.

Abstract: Herein is reported a method for the detection of free antigen of a multispecific antibody in a sample, whereby the antigen to be detected can be specifically bound by a first binding site of the multispecific antibody, comprising the step of incubating a sample comprising free antigen and multispecific antibody with an anti-idiotypic antibody, which specifically binds to a second binding specificity of the bispecific antibody, which is different from the first binding specificity, whereby the anti-idiotypic antibody is bound to a solid phase.

Abstract: The invention provides anti-variant Fc-region antibodies which specifically bind to an antibody that has the mutation P329G or the mutations P329G/L234A/L235A or the mutations I253A/H310A/H435A in the Fc-region, and methods of using the same.

Abstract: Herein is reported a method for the detection of free antigen of a multispecific antibody in a sample, whereby the antigen to be detected can be specifically bound by a first binding site of the multispecific antibody, comprising the step of incubating a sample comprising free antigen and multispecific antibody with an anti-idiotypic antibody, which specifically binds to a second binding specificity of the bispecific antibody, which is different from the first binding specificity, whereby the anti-idiotypic antibody is bound to a solid phase.

Abstract: One aspect as reported herein is a method for detecting a rat antibody in a serum or plasma sample (obtained) from a mouse comprising the steps of a) providing the sample to be analyzed, b) incubating said serum or plasma sample with an antibody that specifically binds to rat IgG and that does not specifically bind to mouse IgG, wherein the antibody is i) a mixture of an antibody binding to rat kappa light chain and an antibody binding to rat lambda light chain, or ii) a mixture of an antibody binding to rat IgG1 with an avidity of 4.1×1010 M?1 or more, an antibody binding to rat IgG2a with an avidity of 8.6×109 M?1 or more, an antibody binding to rat IgG2b with an avidity of 6.4×1010 M?1 or more and an antibody binding to rat IgG2c with an avidity of 9.

Abstract: The invention provides anti-variant Fc-region antibodies which specifically bind to an antibody that has the mutation P329G or the mutations P329G/L234A/L235A or the mutations I253A/H310A/H435A in the Fc-region, and methods of using the same.

Abstract: Herein is reported a method for the detection of free antigen of a multispecific antibody in a sample, whereby the antigen to be detected can be specifically bound by a first binding site of the multispecific antibody, comprising the step of incubating a sample comprising free antigen and multispecific antibody with an anti-idiotypic antibody, which specifically binds to a second binding specificity of the bispecific antibody, which is different from the first binding specificity, whereby the anti-idiotypic antibody is bound to a solid phase.

Abstract: Herein are reported the cell lines DSM ACC3006, DSM ACC3007, and DSM ACC3008, as well as the antibodies obtained from the cell lines and the use of an antibody obtained from the cell lines in an immunoassay. Also are reported antibodies binding to human or chimpanzee IgG and not binding to canine and marmoset IgG and antibodies specifically binding to an IgG 1 that comprises a kappa light chain constant domain.

Abstract: Herein is reported a method for the detection of free antigen of a multispecific antibody in a sample, whereby the antigen to be detected can be specifically bound by a first binding site of the multispecific antibody, comprising the step of incubating a sample comprising free antigen and multispecific antibody with an anti-idiotypic antibody, which specifically binds to a second binding specificity of the bispecific antibody, which is different from the first binding specificity, whereby the anti-idiotypic antibody is bound to a solid phase.

Abstract: The invention provides an antibody binding specifically to Cynomolgus IgG characterized by not binding to Human IgG, and a method for the immunological determination of an immune complex (DA/ADA complex) of a drug antibody (DA) and an antibody against said drug antibody (anti-drug antibody, ADA) in a sample of a monkey species using a double antigen bridging immunoassay.

Abstract: One aspect as reported herein is a method for detecting a rat antibody in a serum or plasma sample (obtained) from a mouse comprising the steps of a) providing the sample to be analyzed, b) incubating said serum or plasma sample with an antibody that specifically binds to rat IgG and that does not specifically bind to mouse IgG, wherein the antibody is i) a mixture of an antibody binding to rat kappa light chain and an antibody binding to rat lambda light chain, or ii) a mixture of an antibody binding to rat IgG1 with an avidity of 4.1×1010 M?1 or more, an antibody binding to rat IgG2a with an avidity of 8.6×109 M?1 or more, an antibody binding to rat IgG2b with an avidity of 6.4×1010 M?1or more and an antibody binding to rat IgG2c with an avidity of 9.

Abstract: Herein is reported an anti-drug antibody immunoassay for the determination of the presence of an anti-drug antibody against an effector function suppressed human or humanized drug antibody in a sample comprising the incubation of a sample comprising mammalian blood serum with full length human Fcgamma receptor I or an Fc-region binding fragment thereof so that a complex between the anti-drug antibody against the effector function suppressed human or humanized drug antibody present in the sample and the human Fcgamma receptor I or the Fc-region binding fragment thereof forms, whereby the full length human Fcgamma receptor I or the Fc-region binding fragment thereof is conjugated to a detectable label, and the determination of the formed complex by the detectable label.

Abstract: Herein are reported a monoclonal antibody specifically binding to a human IgG1 antibody and not specifically binding to the immunoglobulin of an experimental animal and the use of the antibody in immunoassays.

Abstract: Herein is reported a method for the detection of free antigen of a multispecific antibody in a sample, whereby the antigen to be detected can be specifically bound by a first binding site of the multispecific antibody, comprising the step of incubating a sample comprising free antigen and multispecific antibody with an anti-idiotypic antibody that specifically binds to a second binding site of the multispecific antibody, which is different from the first binding site, and thereby depleting the multispecific antibody from the sample.

Abstract: One aspect as reported herein is a method for detecting a rat antibody in a serum or plasma sample (obtained) from a mouse comprising the steps of a) providing the sample to be analyzed, b) incubating said serum or plasma sample with an antibody that specifically binds to rat IgG and that does not specifically bind to mouse IgG, wherein the antibody is i) a mixture of an antibody binding to rat kappa light chain and an antibody binding to rat lambda light chain, or ii) a mixture of an antibody binding to rat IgG1 with an avidity of 4.1×1010 M?1 or more, an antibody binding to rat IgG2a with an avidity of 8.6×109 M?1 or more, an antibody binding to rat IgG2b with an avidity of 6.4×1010 M?1or more and an antibody binding to rat IgG2c with an avidity of 9.

Abstract: One aspect as reported herein is a method for detecting a rat antibody in a serum or plasma sample (obtained) from a mouse comprising the steps of a) providing the sample to be analyzed, b) incubating said serum or plasma sample with an antibody that specifically binds to rat IgG and that does not specifically bind to mouse IgG, wherein the antibody is i) a mixture of an antibody binding to rat kappa light chain and an antibody binding to rat lambda light chain, or ii) a mixture of an antibody binding to rat IgG1 with an avidity of 4.1×1010 M?1 or more, an antibody binding to rat IgG2a with an avidity of 8.6×109 M?1 or more, an antibody binding to rat IgG2b with an avidity of 6.4×1010 M?1 or more and an antibody binding to rat IgG2c with an avidity of 9.

Abstract: Herein are reported a monoclonal antibody specifically binding to a human IgG1 antibody and not specifically binding to the immunoglobulin of an experimental animal and the use of the antibody in immunoassays.