Q.     What grade of helium is used with the PDS1000/He?
A.     Compressed helium of grade 4.5 (99.995%) or higher must be used. Lower grades may contain contaminating material, which can obstruct gas flow within the system, as well as contaminate the biological sample. [Top]

Q.     How is the Biolistic Purchase/Demonstration Agreement processed?
A.     The signed original Purchase/Demonstration Agreement must be on file in the Hercules, CA office prior to shipment of a unit. The Agreement is also required if the unit is to remain in a user's lab on loan for demonstration purposes. Only one Agreement is needed per user/laboratory. Faxed copies of signatures are not legally valid, so we recommend that the signed original document be delivered to the address noted on the form by overnight courier service (DHL, Fed X) for efficient processing and shipment. [Top]

Q.     What is the Upper size range of DNA that can be coated onto particles for Biolistic Gene Gun delivery?
A.     Large Plasmids or naked DNA up to 20-25kb works well in Biolistics. Cosmids, YAC's and other larger DNA vectors can suffer from shearing effects during the precipitation and "shooting" of the gold particles. [Top]

Q.     What's the difference between the Helios Gene Gun and the PDS-1000He?
A.     Both instruments deliver DNA and RNA carried on micron-sized gold particles into a wide variety of cells using pressurized helium, i.e.the Biolistic process. The Helios Gene Gun is a hand-held instrument which is made for in vivo transfection into animal or plant tissues in a 2cm diameter target area. The PDS-1000He is an in vitro benchtop instrument that has a vacuum sample chamber for more controlled particle delivery into animal or plant cell culture or tissues over a 9cm diameter target area. Some laboratories may need both instruments depending on the range of their gene transfer targets. [Top]