In the past, this issue has arisen mainly in connection with biotechnological inventions.

Art. 53(a) EPC is supplemented by R. 28 EPC, which sets out four categories of biotechnological inventions excluded from patentability under that article. R. 28 EPC is part of the chapter on "Biotechnological inventions" inserted into Part II of the Implementing Regulations, and is identical to Art. 6(2) of the Biotech Directive. The Biotech Directive was thereby transposed into European patent law.

Where an invention falls under one of the categories set out in R. 28 EPC, it is by its very nature non‑patentable and there is no need additionally to consider Art. 53(a) EPC. However, if it does not fall under one of those categories, it must be examined more closely under Art. 53(a) EPC (T 315/03, OJ 2006, 15; see also G 2/06, OJ 2009, 306).

R. 29 EPC governs the patentability of the human body and its components. Under R. 29(2) EPC (R. 23e(2) EPC 1973), an element isolated from the human body or otherwise produced by a technical process, including the sequence or a partial sequence of a gene, may constitute a patentable invention, so that an invention falling under this category is not excluded from patentability pursuant to Art. 53(a) EPC (T 272/95 of 23 October 2002 date: 2002-10-23; see also T 1213/05).