Bio-Rad PDS-1000 / He™ and Hepta™ Systems User Manual

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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).