Method of determining an immunogenic response characteristic of a chemical substance

A method of determining an immunogenic response characteristic of a chemical substance, the method comprising

• obtaining a biological liquid sample comprising the chemical substance,
• providing at least one prepared sample from at least a portion of the biological liquid sample,
• for each prepared sample, subjecting at least a test portion of the prepared sample to a flow involving that the test portion of the prepared sample is in contact with a binding partner for the chemical substance, wherein the binding partner comprises an optical marker,
• performing at least one read out of the optical marker;
• determining a characteristic flow parameter of the marked binding partner in contact with the prepared sample based on said at least one read out of the optical marker and
• comparing the determined characteristic flow parameter with at least one reference value and determining the immunogenic response characteristic of the chemical substance, comprising determining if the immunogenic response characteristic is indicative for a non-immunogenic response, an immunogenic response involving generated neutralizing antibodies (NAb) or an immunogenic response involving generated non-neutralizing antibodies (non-Nab).