Bio-Rad Helios® Gene Gun System - Manual (Page 27)

Procedure
1. Examine the coated the Gold-Coat tubing to verify that the microcarriers are evenly dis-
tributed over the length of the tubing. Ideally, the gold should be spread uniformly over the
entire inside surface of the tubing; however, while drying, it may polarize to one side of the
tubing. As long as there are no clumps or bare sections, the tubing can be used for cartridges.
2. Using scissors, cut off and discard sparsely and unevenly coated tubing from one of the
ends. With a marking pen mark any sections of tubing to be discarded. This is usually
limited to the outer 1–2" where the gold has settled, but may also include internal sections
of tubing which are un unevenly coated with gold.
3. Use the Tubing Cutter to cut the remaining tubing into 0.5" pieces as follows:
a. Place a cartridge storage vial containing a desiccant pellet inside the base of the Tubing
Cutter.
b. Insert the cut ends of one or two pieces of tubing into the tubing channels on the front
face of the Tubing Cutter (Figure 7); be sure to push them in until they make contact
with the rear plate.
c. Push down sharply on the handle; the tubes will drop into the storage vial.
d. Repeat the process of inserting the uncut tubing and cutting the cartridges until the
entire length of usable tubing is cut.
4. Cap the vial tightly, label, wrap with Parafilm, and store at 4 °C.
5.3 Particle Delivery Using the Helios Gene Gun
This section describes the procedure for preparing the Helios Gene Gun for firing, discharg-
ing the device, loading cartridges into the cartridge holder, and delivering DNA to target cells.
(Warning: Use the Helios Gene Gun in a well ventilated area.)
Materials
Supplied
Helios Gene Gun
Barrel liner (see Section 10.5 on sterilization)
Cartridge holder
Helium hose
Helium regulator (see Section 4.2)
To be Supplied by User
Helium tank (see Section 2.4)
Ear protection
Cartridges with coated microcarriers (from Section 5.2)
Activating the Helios Gene Gun for Gene Delivery
When first setting up the system and prior to discharging the Gene Gun into a target, it is
important to pressurize the helium hose and the internal reservoirs of the gun with the correct
helium pressure. This is accomplished by discharging the device prior to delivering loaded
tubes to the target cells. It is important to have a cartridge holder in place during these
“pre-shots” to keep the O-rings from being blown out (see Section 10.2).
1. Insert an empty cartridge holder into the Helios Gene Gun as follows:
a. Move the cylinder lock on the Gene Gun so it is latched in the forward position and the
barrel pin does not protrude behind the barrel (Figure 12).
b. Unlatch the push bar by pulling it outward (Figure 12).
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