Trilateral Project 24.1-Biotechnology 170

Generally, when the whole DNA sequence of a structural gene is known, preparing any partial DNA fragment of the said structural gene is within the range of ordinary creative ability which is commonly displayed by a person skilled in the art, because it is easily prepared by using combination of appropriate ligases and nucleases or by chemical synthesis.

Therefore, generally inventive step cannot be recognized in this case.

However, if the effect which such a partial DNA fragment has is either qualitatively different over prior art or quantitatively better even if its quality is the same so that the effect cannot be expected by a person in the art on the basis of the state of the art, inventive step is present.

Case 1) and 2) below can be assumed as examples to which such determination would be applied.

1) When the polypeptide related to the partial DNA fragment maintains the same biological activity as the said functional polypeptide.

Generally, when a certain protein possessing a biological activity is known, the search for the position of the active site in the protein molecule is a problem which can be easily come up with by a person skilled in the art.

Furthermore, in order to solve this problem successfully, preparing the said partial DNA sequence with some deletion encoding polypeptide (for instance, the said DNA sequence with deletion of the part of the DNA sequence encoding N- or C-terminal) and looking on the difference in the biological activity of the polypeptide expressed by the said partial DNA is within the range of ordinary creative ability which is commonly displayed by a person skilled in the art.

Thus, in principle, inventive step would not be present if the deletion is within the extent which is considered ordinary by a person skilled in the art.

However, if the advantageous effect obtained by the partial DNA cannot be expected by a person skilled in the art on the basis of the state of the art as of the filing, inventive step would be present.

2) In case that the above structural gene originates in a viral antigen or encodes antigenic protein of certain pathogen causing infectious diseases so that there is a well-founded reason that the partial DNA fragments of the said structural gene would be useful as probes for analysis and diagnosis of the infection by the infectious virus.

Inventive step generally cannot be recognized for an invention which merely provide a DNA fragment as a prove, because advantageous effect of the DNA fragment is no more than what can be expected by a person skilled in the art.

However, when the specification discloses that a claimed specific partial DNA fragment is suitable in particular for a probe for analysis or examination (or has different utility), and when a person skilled in the art cannot expect this effect on the basis of the state of the art as of the filing, the claimed invention has inventive step.