If an invention involves the use of or concerns biological material which is not available to the public and which cannot be described in the European patent application in such a manner as to enable the invention to be carried out by a person skilled in the art, the invention shall only be regarded as being disclosed as prescribed in Art. 83 EPC if a sample of the biological material has been deposited with a recognised depositary institution not later than the date of filing of the application (R. 31(1)(a) EPC) and if the application fulfils the other requirements set out in R. 31 EPC (see also G 2/93, OJ 1995, 275).

The disclosure of a microorganism need not depend on a deposit according to R. 28 EPC 1973 where the microorganism is sufficiently disclosed by other means (T 2068/11; cited recently by T 1338/12 very detailed on this issue).

As part of the 2000 EPC revision, for greater clarity and consistency, R. 27a, 28 and 28a EPC 1973 were restructured, trimmed and incorporated (as R. 30 to 34 EPC) into the chapter on biotechnological inventions (see OJ SE 1/2003, 164, OJ SE 5/2007, 44 and OJ SE 5/2007, 54). New R. 31 EPC deals with the deposit of biological material, new R. 32 EPC with the expert solution and new R. 33 EPC with the availability of the deposited biological material as from the date of application of the European patent application (OJ SE 5/2007, 46; see also OJ 2017, A55 (CA/D 3/17), OJ 2017, A60 and A61 (Notice)).