Appeal No. 97-0480
Application No. 07/858,818
particles on the other side of the plate, (2c) by stopping a fired macroprojectile bullet, which contains
particles in a forward cavity thereof, with a device which allows the particles to pass through and
continue ahead at full speed, (2d) by allowing particles attached to or dispersed on the perimeter of a
high speed rotor to escape tangentially therefrom, or (2e) by electrostatically accelerating charged
particles (Figs. 2a-2e; col. 4, lines 20-38). Generally, the particles should be small enough to produce
minimal cell damage and large enough to acquire sufficient momentum to penetrate the cell; momentum
being a function of size, density and velocity, with sufficient integrity to withstand the physical forces
inherent in the process (col. 5, lines 38-66). Exemplary particles include inert particles, e.g., gold or
tungsten spheres (col. 6, lines 39-44) and subject cells include plant pollen and plant protoplasts (col. 7,
lines 27-31). Examples 1 and 3 show delivery of tungsten spheres into onion epidermal cells using a
shot of compressed gas blast (Fig. 7; col. 7, line 49 - col. 8, line 27; col. 11, line 10 - col. 12, line 3)
and macroprojectile “bullet” acceleration of particles (Figs. 2b and 2c; Fig. 8; col. 8, line 52 - col. 9,
line 2; col. 12, lines 22-53), respectively.
According to the examiner, Sanford “would have anticipated the invention but for the fact that
the particles delivered to the onion epidermal cells were not coated with DNA” (Answer, page 8, first
paragraph). The examiner relies on Klein to show ballistic acceleration of DNA-coated particles into
onion epidermal cells and concludes that it would have been obvious to one of ordinary skill in the art to
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