Bio-Rad Helios® Gene Gun System - Manual (Page 31)

Notes: (1) The firing trigger is functional only while the safety interlock switch is pushed
in. The safety interlock switch activates the trigger button for 30 sec; if the Gene Gun is
not fired within the 30 sec period, the safety interlock switch must be released, then
pressed again to reactivate it. (2) After firing the gun, there is a 5 sec delay before the
gun may be fired again. (3) Advance the cartridge holder by squeezing the cylinder
advance lever between each shot.
Fig. 16. Position of hand over the safety interlock switch in preparation for firing.
5. Removing the cartridge holder from the Helios Gene Gun is accomplished as follows:
a. Move the cylinder lock on the Gene Gun forward and to the right so it is latched and
the barrel pin does not protrude behind the barrel (Figure 12).
b. Unlatch the push bar by pulling it outward.
c. Pull back and hold the cylinder advance lever to retract the inner barrel sleeve into the
gun barrel (Figure 13).
d. Pull the cartridge holder up and out of the Gene Gun. The gun will turn-off after 3 min.
Loading Cartridges into the Helios Gene Gun
Each cartridge holder has slots for 12 cartridges. Each slot is numbered along the edge of
the cartridge holder, as seen when loading. The numbers correspond to the firing order when
the cartridge holder is properly positioned in the Gene Gun. The cartridge holder should be
loaded with cartridges beginning with position 1, then clockwise through position 12 (see
Figure 17). Note, however, that the cartridge that is in firing position is at the bottom of the
cartridge holder when it is inserted in the Gene Gun. Therefore, the cartridge in firing posi-
tion will not be visible to the user but will be indicated by the number at the top of cartridge
holder and visible along the cartridge rim.
1. Place the cartridge holder on a flat surface with the numbered edge facing up.
2. Starting with position 1, load up to 12 cartridges into the cartridge holder (Figure 17).
We recommend loading only one type of DNA per cylinder to avoid possible confusion.
3. Invert the cartridge holder and push the cartridges against a flat surface so that they are
flush with the numbered side of the cylinder.
4. Insert the loaded cartridge holder into the Helios Gene Gun as described above. When the
LED on the back of the Gene Gun indicates that the first cartridge is in firing position
(Figure 15) the device is ready to deliver DNA.
27