A patent application is judged on four criteria. In general, raw products of nature are not patentable. It's usually when these DNA products have been isolated, purified, or modified to produce a unique form not found in nature that they become patentable. In Europe, the timeframe is 18 months. Patents are good for 20 years from filing date.
Inventors have a one-year grace period to file after they publish.
Many biotech patents have been applied for as provisional patents. This means that persons or companies filing the provisional patent application have up to one year to file their actual patent claim. The provisional patent must contain a written description of said invention and the names of the inventors. This one-year grace period does not count as one of the 17 years that the patent is issued for. When a biotechnology patent involving an altered product of nature is issued, the patent holder is required to deposit a sample of the new invention into one of the 26 worldwide culture depositories.