Appeal No. 97-0480
Application No. 07/858,818
Sanford et al. (Sanford) 4,945,050 Jul.31, 1990
(filed Nov. 13, 1984)
Klein et al. (Klein), Program and Abstracts for an International Symposium
Biotechnology in Plant Science: Relevance to Agriculture in the Eighties, “Particle Gun
Technology: A Novel Method for the Introduction of DNA into Living Cells,” organized by the Cornell
University Biotechnology Program, Ithaca, NY, June 23-27, 1985, Poster #28.
Sanford et al., (Sanford “R”), “Delivery of Substances into Cells and Tissues Using a Particle
Bombardment Process,” 5 Particulate Science and Technology, 1987: 27-37).3
Appellants’ claimed invention is directed to a method of introducing cloned genes into living
plant cells by physically bombarding the cells with accelerated DNA-coated carrier particles. The
DNA-coated carrier particles are placed on a carrier sheet which is then placed above a pair of spaced
electrodes having a gap therebetween bridged by a water droplet. A retaining screen is placed a
selected distance above the carrier sheet. The cells are placed on a target surface a selected distance
above the retaining screen. Electric voltage is applied to the electrodes to create an electric discharge
which vaporizes the water droplet, thereby releasing energy, i.e., producing a shock wave. The
released energy impacts and accelerates the carrier sheet until it is stopped by the retaining screen
whereupon the carrier particles leave the carrier sheet, pass through the screen and continue on
penetrate the target cells. According to appellants, accelerating a planar carrier sheet coated with
evenly distributed carrier particles towards the target surface allows the carrier particles to impact the
3We note that the examiner did not include the Sanford “R” reference in her list of the prior art of record
on page 3 of the Answer.
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