| 摘要 |
<p>In a method of marking an animal or plant, at least one stable isotope of an element, which element is naturally present in the said animal or plant, is administered to the animal or plant. The amount of the isotope or the relative amounts of the isotopes administered are so selected that the ratio of two or more isotopes of the said element to one another in the animal or plant differs from the ratio usually found in such animals or plants. A product derived from the animal or plant to which the isotope or isotopes have been administered may subsequently be identified by virtue of the deviation of the ratio from that usually found.</p> |
