PCT rules stipulate that no International Searching Authority (ISA) is required to search and no International Preliminary Examining Authority (IPEA) is required to examine an international application if its subject matter is "plant or animal varieties or essentially biological processes for the production of plants and animals, other than microbiological processes and the products of such processes" (PCT Rule 39.1 and PCT Rule 67.1). Some national and regional patent offices deny patent protection to such subject matter or related subject matter, although many provide other protections for novel plant and animal varieties.
In the U.S., for example, patent protection can be obtained for asexually reproduced plants under both 35 U.S.C. 101 and 35 U.S.C. 161. In the U.S., non-patent protection of sexually reproduced plants can be obtained under the Plant Variety Protection Act. Nineteen countries, including the U.S., are party to the International Convention for the Protection of New Varieties of Plants (UPOV). The USPTO has granted patents to "nonnaturally occurring, nonhuman multicellular living organisms, including animals" (MPEP 2105).
EPO rules deny patentability to "plant or animal varieties or essentially biological processes for the production of plants or animals." These rules also note, however, that patents may be obtained for technical inventions that involve biological processes, and give examples such as "a method of pruning a tree," "a method of treating a plant characterized by the application of growth stimulating substance or radiation" or "the treatment of soil by technical means to suppress or promote the growth of plants."
Because one of the primary advantages of filing an international application is that a thorough search and preliminary examination will provide some assurance that national applications will be successful, an applicant may be well advised not to file an international application if the subject matter falls into the above areas. If the USPTO ISA or IPEA conducts the international search or preliminary examination, however, it will search and examine all subject matter searched and examined in U.S. national patent applications.