Bio-Rad PDS-1000 / He™ and Hepta™ Systems - Manual (Page 26)

Firing the Device
1. Plug in power cord from main unit to electrical outlet.
2. Power ON.
3. Sterilize chamber walls with 70% ethanol.
4. Load sterile rupture disk into sterile retaining cap.
5. Secure retaining cap to end of gas acceleration tube (inside, top of bombardment cham-
ber) and tighten with torque wrench.
6. Load macrocarrier and stopping screen into microcarrier launch assembly.
7. Place microcarrier launch assembly and target cells in chamber and close door.
8. Evacuate chamber, hold vacuum at desired level (minimum 5 inches of mercury).
9. Bombard sample: Fire button continuously depressed until rupture disk bursts and heli-
um pressure gauge drops to zero.
10. Release Fire button.
After the Bombardment
1. Release vacuum from chamber.
2. Target cells removed from chamber.
3. Unload macrocarrier and stopping screen from microcarrier launch assembly.
4. Unload spent rupture disk.
5. Remove helium pressure from the system (after all experiments completed for the day).
Detailed Operation Procedure
Note: We recommend that the first bombardment each day be a “dry run” with no target
cells or microcarriers to ensure that the system is set up properly and the gas pathway is
filled with helium, not air.
1. Power On
With the unit plugged in to the appropriate electrical outlet or voltage converter, turn on the
unit by pressing the ON switch. This is the left-most red control panel switch (Figure 2.9).
2. Helium Pressure
Confirm that the helium tank pressure regulator is set to 200 psi over the selected rupture disk
burst pressure (e.g., set the regulator to 1,100 psi when working with a 900 psi rupture disk).
3. Pressurizing the System with Helium
Make certain that the helium pressure regulator is properly installed on the helium tank
(see Set-up).
Close the helium pressure regulator by turning the regulator adjustment screw counter-
clockwise until the adjusting spring pressure is released.
Release helium into the pressure regulator by carefully and slowly opening the cylinder
valve on the helium tank. The cylinder pressure in the tank is indicated on the high pres-
sure gauge (the gauge closest to cylinder).
Set the desired helium delivery pressure for the rupture disk you are using (measured on
gauge on the outside, farthest from cylinder) by turning the regulator adjustment handle
clockwise. The pressure should be set to 200 psi above the rupture disk rating.
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