Interpretative Spotlight : “about”

Claim 1 of the request under consideration read:

1. A method for cultivating L.intracellularis bacteria comprising obtaining culture cells infected with L.intracellularis, incubating said infected cells at an oxygen concentration of less than about 18 percent while maintaining said infected cells in suspension, wherein harvesting is done when greater than about 70% of the cells as determined by the TCID50 method are infected.

[7] An objection for lack of clarity was raised against the term “about” in the expression “wherein harvesting is done when greater than about 70% of the cells as determined by the IFA method are infected”. In accordance with the case law (e.g. T 190/99), a patent must be construed by a mind willing to understand, not a mind desirous of misunderstanding. Here, the skilled person would be fully aware that, because of the number of parameters which may influence cell growth, it will not be possible exactly to predict when the number of cells will reach a defined mathematical value (70%). Yet, he/she would have no problem in evaluating when the cell culture has reached an essentially equivalent stage (here “about 70%”).

For this reason, there is no lack of clarity in claim 1.

To read the whole decision (T 692/08), click here.