Bio-Rad Helios® Gene Gun System - Manual (Page 13)

Fig. 5. Components and controls on the Helios Gene Gun.
Gene Gun Controls Description
Cylinder Lock Controls movement of the barrel pin. The cylinder lock is
spring-loaded; its natural position is in the backward (locked)
position so the barrel pin is inserted in the hole in the cartridge
holder; this keeps the cartridge holder in its proper position for
firing. Moving the cylinder lock forward disengages the barrel
pin from the cartridge holder to permit removing the cartridge
holder from the gun. Moving the cylinder lock forward and to
the right latches the cylinder lock to permit removal of the
cartridge holder; however, to prevent damage to the O-rings,
the cartridge holder should only be removed after compressing
the cylinder advance lever (see below).
Safety Interlock Switch Switch that must be held down to permit the trigger button to
be operational. Once this switch is depressed, the trigger button
is functional for 30 sec; the LED ARMED display flashes
quickly during this time. If the trigger button is not pressed
within the alloted time, this safety interlock switch must be
released and pressed again to re-activate the trigger button.
Trigger Button Controls the flow of helium gas through the Gene Gun. This switch
activates the solenoid, momentarily (for ~40 msec) opening the main
valve, and permitting helium to enter the cartridge and barrel. The
trigger button is only active for 30 sec after the safety interlock switch
is depressed.
Cylinder Advance Lever A multi-functional lever which is spring-activated by pulling the
lever backwards. When inserting or removing a cartridge holder,
pull back and hold in the cylinder advance lever; this moves the
barrel liner forward to provide additional room for maneuvering
the cartridge holder. After discharging the microcarriers from one
cartridge, pull back and release the cylinder advance lever; this
ratchets the cartridge holder, bringing the next cartridge into firing
position—the number visible on the very top of the cartridge rim
indicates the active sample position.
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