Bio-Rad PDS-1000 / He™ and Hepta™ Systems - Manual (Page 31)

9. Target cells/tissue placement in chamber
Place the Target Shelf at the desired level inside the bombardment chamber. Place the
sample (usually contained within a Petri dish) on the Target Shelf. Close and latch the sam-
ple chamber door.
10. Chamber evacuation/hold
Turn on the vacuum source. Set the vacuum switch on the PDS-1000/He (middle red
control switch, Figure 4.11) to the VAC position. Evacuate the sample chamber to the
desired level, at least 5 inches of mercury. The rightmost red control switch (the FIRE
switch) will be illuminated when the minimum vacuum is achieved.
When the desired vacuum level is reached, hold the chamber vacuum at that level by
quickly pressing the vacuum control switch through the middle VENT position to the
bottom HOLD position.
Fig. 4.11. Sample bombardment: power switch ON, vacuum switch on HOLD position, and user
continuously pressing FIRE button.
11. Bombard the sample
With the vacuum level in the bombardment chamber stabilized, press and hold the FIRE
switch to allow helium pressure to build inside the gas acceleration tube that is sealed by
a selected rupture disk (Figure 4.11).
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