Whilst methods of diagnosis are patentable in most countries, the wording of the patent claims often has to be chosen very carefully in order to avoid exclusions which are present in many patent laws.


Examples of method of diagnosis claims

Diagnostic assays are generally claimed as methods which refer to the key steps which are involved to obtain the diagnosis, for example:

  1. A method of diagnosing Alzheimer’s disease, the method comprising the steps:
    i. Isolating blood cells from a blood sample obtained from a patient; and
    ii. Determining the presence or absence of BLA4 protein in the isolated blood cells,

wherein the presence of BLA4 protein in the total protein is indicative of Alzheimer’s disease in the patient.


Method of diagnosis patents in the US

In 2012, the US Supreme Court ruled that patents which were based on a correlation between a biomarker and a disease were not allowed because they were attempting to monopolise a ‘law of nature’. The US district/appeal courts and the USPTO are still trying to resolve how the Supreme Court’s decision should be applied in practice, but the decision has already had a significant impact in some areas (e.g. preventing the patenting of some pre-natal diagnostic methods). This decision only applies to US patents