The present invention describes a method of performing immunoassay measurements on whole blood samples for biomarker quantification. These tests are routinely performed on serum or plasma separated from whole blood samples. Prior art also involves application of complex multi-component assays or methods using insoluble particles for these measurements. A solution capable of working on whole blood samples, offering advantages in assay simplicity, cost-effectiveness and shortened measurement times was desired. The present invention solves these issues using simple immunoturbidimetry for whole blood samples without relying on particle enhancement of the reaction. To achieve this goal the agglutination reaction between antibodies and antigens is performed, measured and evaluated according to the disclosed method for whole blood assays.