The Issue of Repeatability

Date Published

The main difference between inventions involving living and non-living systems is that many processes involving living systems are not 100% repeatable. In some cases the probability of repeating the invention, even using the best method known to the applicant, can be very low.

Each art has its own standard of repeatability and this must be taken into consideration when assessing repeatability of an invention. The issue when considering repeatability is not the numerical probability of achieving the specified result, but whether the result can be reproduced to a practical level acceptable to a person skilled in the art.

The result of chance mutation is not patentable on the grounds of lack of practical repeatability. For example, in a case involving the 'Scarlet Queen Elizabeth' rose, it was held that the process of production of the plant was not sufficiently disclosed because it was a chance genetic mutation. It was estimated that the probability of repeating this mutation was 1 in 100,000,000, which was impractical, if not impossible, given the methods of reproduction available at that time.

In situations where the repeatability is doubtful, but there is no clear indication that the invention is the result of a chance mutation, it is Office practice to accept that a best method of performance is established by the presence of a description of the process and a statement in the specification such as:

"It is practical to repeat the invention using current state of the art techniques to carry out the number of trials necessary to achieve the desired result."

It should be noted that some microbiological work which is automated and/or carried out by computer involves millions of trials, and such numbers may clearly be practical in certain fields.

Note: The requirement of repeatability may be met through a deposit under the Budapest Treaty (see 2.7.3 The Budapest Treaty).