Appeal No. 2002-1359
Application No. 09/323,990
claimed subject matter differs from the disclosure of Wan in that “a vortex chamber is
specifically utilized to carry out the claimed method of processing cells.” Id.
The examiner concludes (Paper No. 4, page 4):
It would have been obvious to one of ordinary skill in the art at the time
of applicant's invention to substitute the static mixer of Wan et al. with the
fluid vortex mixer disclosed by the UK Patent [Bowe] in order to obtain a
method for processing cells using a fluidic vortex mixer. Clearly one of
ordinary skill would have been motivated to provide for a flow through
device having a helical structure as Wan et al. describes that the
dimensions and flow of the cell suspension for purposes of cell lysis is
critical to the process. A fluid vortex mixer possesses the same properties
as any flow through device. Wan et al. clearly teach that any flow through
device may be used as long as it is static or motionless. The UK Patent is
silent with respect to whether or not the vortex mixer is static or
motionless, however, in its teaching it clearly provides disclosure that the
liquid or aqueous suspension spirally flows through the vortex indicating
that there is no motion provided to support the vortex mixer but only that
the fluid is allowed to flow through the device. Furthermore, residence
time is suggested by Wan et al. in that the disclosure teaches that the
dimension must be of appropriate length in order to provide enough
contact time between the lysing agent and the cells to cause lysis during
the passage through the mixer ... Clearly residence time is suggested, if
not taught, by Wan et al. and that such time is required to be sufficient for
cell lysis to be completed.
[Emphasis added.]
Appellant argues that “Wan et al. refer to a method of lysing cells in which a cell
suspension and a lysis solution are passed through a static mixer (i.e., a pipe with
stationary baffles) wherein the cells exit the static mixer lysed. An essential aspect of
the Wan et al. process is that lysis has finished by the time that the cells have left the
static mixer. Hence, residence time in the mixer must be sufficiently long to ensure that
lysis has occurred. For example, they state that there must be 'enough contact time
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