Method for evaluation of target in histological sample

A method for detecting a target in a target site on one or more cells in a histological sample, wherein the target site comprises a binding partner for a binding agent, comprising,

• (a) incubating the sample presumably comprising the target in one or more target sites in an incubation medium comprising the a binding agent that is capable of specifically binding to the binding partner comprised in said one or more target sites on one or more cells,
• wherein the amount of the binding agent in the incubation medium is sufficient to bind to at least 51% of the binding partners present in the sample, and
• wherein the binding agent comprises a population of first binding molecules and a population of second binding molecules,
• wherein the first binding molecule comprises a binding part and a detectable part, and the second binding molecule comprises a binding part,
• wherein the binding part of the first binding molecule and the binding part of the second binding molecule are both capable of specifically binding to the binding partner and competing against each other for said binding,
• wherein the first binding molecule comprises an antibody molecule, or a derivative thereof, comprising an Fc region, and
• wherein the second binding molecule does not comprise a part that can be detected by a detector of the detectable part of the first binding molecule and the second binding molecule does not comprise the Fc region of the first binding molecule;
• and
• (b) detecting the detectable parts of the first binding molecules of the binding agent on one or more cells in the sample.