A focusing device for tissue transformation with the DuPont/BioRad PDS1000 helium microprojectile system

The DuPont/BioRad PDS1000/He has become an important tool in genetic transformation. With the present design, however, it is difficult to accurately predict the impact area. This report discusses targeting devices that were designed to accurately focus biolistic particles in a given area. Tobacco leaves and soybean tissue were used to evaluate the efficiency of the device. With the focusing device, GUS positive foci were confined in a defined ring on soybean cotyledonary nodes. Approximately 65 percent of the GUS positive foci on tobacco leaves were concentrated in a ring 8 to 16 mm from the center of the short, compared to 27 percent without the device. The results demonstrate that PDS-1000 biolistic particles can both be accurately and predictably delivered at target tissue.