Bio-Rad PDS-1000 / He™ and Hepta™ Systems - Manual (Page 22)

3. Prepare the Rupture Disk Retaining Cap. After setting the gap between cap and micro-
carrier launch assembly, wrap the Rupture Disk Retaining Cap in aluminum foil and ster-
ilize by autoclaving.
4. Prepare the Microcarrier Launch Assembly.
The effect of the gas shock wave on the microcarrier velocities is determined in part by
the gap between the rupture disk and the macrocarrier.
The macrocarrier flight distance can be adjusted by varying the positions of the stopping
screen support and the spacer rings inside the fixed nest (Figure 4.2). The Stopping Screen
Support is placed in the middle position at the factory. This is the recommended position
when initially optimizing bombardment parameters.
To make this adjustment, remove the microcarrier launch assembly from the PDS-1000/He
unit. Unscrew and remove the macrocarrier cover lid. Disassemble the components of the
microcarrier launch assembly by placing the macrocarrier insertion tool into the bottom of
the assembly and pushing up. This releases the stainless steel fixed nest from the brass
adjustable nest. The two spacer rings and the stopping screen support will fall out from
within the fixed nest.
To change the factory-set position to the position for the minimum macrocarrier travel dis-
tance (6 mm), invert the fixed nest and insert the stopping screen support inside the fixed
nest so that the conical side of the stopping screen support faces down in the final orien-
tation; then insert the two spacer rings (5 mm thickness, each). With the fixed nest still
inverted, place the macrocarrier launch assembly over the fixed nest and seat the fixed nest
within the brass adjustable nest.
If greater macrocarrier travel is desired, rearrange the spacer rings and stopping screen sup-
port accordingly. The macrocarrier travel distance can be increased in two 5 mm steps, to
a maximum of 16 mm.
Sterilize the microcarrier launch assembly by wrapping in aluminum foil and autoclaving.
Alternatively, this assembly can be sterilized by wiping with 70% ethanol, followed by
drying in a sterile environment.
5. Target Shelf
Sterilize the target shelf by wiping with 70% ethanol, followed by drying in a sterile envi-
ronment just prior to use. This part may not be autoclaved.
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