Stopping Plates

Description (Brief)
These stopping plates are samples of the kind used as part of the firing mechanism for a biolistic gene gun prototype produced by John Sanford, Ed Wolf, and Nelson Allen at Cornell University in Ithaca, New York. Biolistic gene guns are used to genetically transform plants, by shooting microprojectiles (tiny bullets) covered in DNA into plant cells.
The firing mechanism of the gene gun required several steps. A gunpowder charge (see object 1991.0785.03.2) or compressed air was used to accelerate a macroprojectile (see object 1991.0785.03.3), upon whose tip rested DNA-coated microprojectiles. The macroprojectile would be halted upon impact with a stopping plate. A hole in the stopping plate was small enough to allow the microprojectiles to pass through, but large enough to halt the macroprojectile (see object 1991.0785.03.5). The microparticles would then continue to move forward, eventually penetrating the cells to be transformed. The process is diagrammed in the Biolistic Gene Transfer Process shadow box (see object 1992.0023.01).
To learn more about biolistic gene guns, please see gene gun prototype II (object number 1991.0785.02) or gene gun prototype III (object number 1991.0785.01.1).
Currently not on view
Physical Description
plastic, lexan, polycarbonate resin thermoplastic (overall material)
overall: 1 in x 3 5/8 in; 2.54 cm x 9.2075 cm
ID Number
catalog number
accession number
See more items in
Medicine and Science: Biological Sciences
Science & Mathematics
Biotechnology and Genetics
Biolistic Gene Guns
Data Source
National Museum of American History


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