T 853/11 – Constantly Craving

This decision contains a useful statement on what the skilled person would do.

Claim 1 of the main request before the Board read:

A method of forming a polymer array comprising a substrate and 100 or more groups of polymers with diverse, known sequences coupled to the surface thereof in discrete, known locations, the density of said groups being at least 1000 per cm², wherein said discrete known locations are separated from one another by inert regions, and wherein said polymers are delivered to said locations by spotting.

When assessing the inventive step involved in the invention under consideration, the Board came to the conclusion that document D3 was the closest prior art and formulated the technical problem to consist in providing an alternative to photolithographic methods for producing high-density screening arrays.

[3.2.1] The [patent proprietor] has however argued that the person skilled in the art would have no motivation to search for an alternative to the method of document D3, i.e. would have no reason for departing from the pioneering and very successful photolithographic techniques which had allowed for the first time to obtain very high probe densities and, in particular, probe densities much higher than the lower limit of 1000 probes per cm² set in the granted claim […].

[3.2.2] The Board considers instead that it is inherently advantageous for the skilled person to also have at his disposal further ways for solving the same technical problems that have already been solved in the prior art. Thus, the fictional skilled person would normally search for and arrive at any obvious alternative to the prior art, independently as to whether the prior art presents or not particular disadvantages or difficulties, as well as independently on the public recognition of the pioneering nature and of the advantages of the prior art.

The Board incidentally notes that even the passage of paragraph [0010] of the description of the patent-in-suit […] appears to imply similar considerations.

The Board notes further that document D3 explicitly mentions the possibility of fabricating arrays with a density of probes of 1000 per cm² or even much less […], thereby proving to the skilled reader thereof that also the variants of this prior art methods resulting in somewhat less dense arrays with a probe density of about 1000 per cm²represent a realistic reduction into practice of the teaching in this citation.

[3.2.3] Hence, the Board concludes that the skilled person would actually attempt to solve the posed technical problem, i.e. would search for further methods for fabricating the arrays that were already delivered by the photolithographic methods, including those for fabricating arrays with a density of probes of about 1000 per cm².

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