BIO RAD Helios Gene Gun System User manual

Helios Gene Gun System
Instruction Manual
Catalog Number #1652431
1652432

II | Helios Gene Gun System
Warranty and Regulatory Notices
Warranty Statement
The Helios Gene Gun System and associated accessories are covered by a standard Bio-Rad warranty. Contactyour
local Bio-Rad Laboratories office for details of the warranty.
Regulatory Notices
Important: This Bio-Rad instrument is designed and certified to meet EN/IEC 61010-1:2010 (3rd Edition), EN61326-
1:2013 Class A, and EN50581:2012 requirements, which are internationally accepted electromagnetic compliance and
electrical safety standards. Certified products are safe to use when operated in accordance with the instruction manual.
This instrument should not be modified or altered in any way. Alteration of this instrument will void the manufacturer’s
warranty, void the regulatory certifications, and create a potential safety hazard.
Note: This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part
15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference when the
equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radiofrequency
energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case
the user will be required to correct the interference at his own expense.

Helios Gene Gun System | III
Table of Contents
Section 1General Safety Information ........................................................1
Helios Gene Gun Safety ..........................................................1
Pressurized Helium and Nitrogen Safety ..............................................1
Power Safety ...................................................................2
Ear and Eye Protection ...........................................................2
Section 2Introduction to Particle Delivery .....................................................3
Particle Delivery Technology .......................................................3
The Helios Gene Gun ............................................................3
Operating Principle of the Helios Gene Gun System .....................................4
Requirements for System Operation .................................................5
User Supplied Components .......................................................6
Section 3Product Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Packing List....................................................................8
Identification of System Components and Controls..................................... 10
Section 4Inserting the Battery into the Helios Gene Gun ........................................ 14
Connecting the Helios Gene Gun to a Helium Source ................................... 15
Setting Up the Tubing Prep Station .................................................16
Section 5Operation of the Helios Gene Gun System ...........................................19
Quick Guide to Operation ........................................................19
Preparation of System Components Prior to Bombardment ..............................20
Particle Delivery Using the Helios Gene Gun System ...................................26
Removing Used Cartridges, Depressurization, and Shutdown ............................31
Section 6Preparation of Mammalian Cell Targets ..............................................32
In Vitro Delivery to Adherent Cells ..................................................32
In Vitro Delivery to Suspension Cultures .............................................33
In Vivo Delivery to Epidermis ......................................................35
Section 7Optimization of Gene Gun Parameters ..............................................36
Overview .....................................................................36
Parameters for In Vitro Delivery ....................................................38
Parameters for In Vivo Delivery ....................................................39
Section 8 Troubleshooting................................................................39
DNA/Microcarrier Preparation .....................................................39
Cartridge Preparation ...........................................................39
Helios Gene Gun Operation ......................................................40
In Vitro and In Vivo Targeting ......................................................40
Section 9 Product Information............................................................. 41
Helios Gene Gun System ........................................................ 41
Spare Parts ...................................................................42
Gene Gun Specifications.........................................................42
Tubing Prep Station Specifications .................................................43
Section 10 Appendices...................................................................43
Precipitation of RNA onto Microcarriers..............................................43
Replacing the O-Rings and Barrel Liner on the Helios Gene Gun ..........................44
Replacing the O-Ring on the Tubing Prep Station ......................................45
Replacement of Razor Blade on and Disassembly of the Tubing Cutter .....................45
Cleaning and Sterilizing the Helios Gene Gun .........................................47
Testing Cartridges for Microcarrier Penetration and Density (Optional) ...................... 47
Quantification of DNA in Cartridges.................................................50
References ................................................................... 51
Quick Guide to Operation ........................................................52

IV | Helios Gene Gun System

Section 1 General Safety Information
Helios Gene Gun System | 1
Section 1 General Safety Information
Section 1
General Safety Information
Caution: In particle bombardment DNA-coated microparticles are accelerated to velocities in excess
of 1,000 ft/sec in order to penetrate the cell membrane and through multiple layers of cells in tissues
and organs. In the Helios Gene Gun, this accelerating force is supplied by a high-pressure helium pulse.
Numerous safety features have been designed into this instrument to protect both the user and bystanders.
The parts used in manufacturing the Helios Gene Gun were chosen because they are designed to work at
the pressures required for operation and have a wide safety margin. General safety principles are indicated
below. Specific safety recommendations are indicated in the appropriate sections throughout the manual.
Helios Gene Gun Safety
Caution: While the Helios Gene Gun has a trigger button that is time-activated by a safety interlock
switch, accidental or unintentional discharge is still possible. Do not point the gun at people. The Helios
Gene Gun is for research use only.
Refer to Connecting the Helios Gene Gun to a Helium Source in Section 4 for setting up a helium source
and to Particle Delivery Using the Helios Gene Gun and Removing Used Cartridges, Depressurization, and
Shutdown, both in Section 5, for instruction on use and depressurization/shutdown, respectively, of the
Gene Gun.
Pressurized Helium and Nitrogen Safety
Caution: Although helium and nitrogen are neither toxic nor flammable, all gases under pressure are
potentially dangerous if used improperly. Always be sure pressurized tanks are properly secured. This may
be accomplished by placing the tank in a floor stand or by using a wall-mounted or bench-mounted strap.
Please follow the instructions provided with the helium tank from the supplier and those that are applicable
for your institution (see your Site Safety Officer). Bio-Rad has supplied tubing, fittings, a control valve, and
a pressure regulator capable of safely handling the high-pressure helium gas used in the Helios Gene Gun.
These components have been carefully selected and are the only parts to be used with the Helios Gene
Gun System.
Refer to Requirements for System Operation in Section 2 for a description of the helium and nitrogen gases
required for the Helios Gene Gun System.

Section 1 General Safety Information
2 | Helios Gene Gun System
Power Safety
Figure 1 shows the serial number certification label, which is found underneath the molded case of
the Helios Gene Gun. This label provides the manufacturing data about the instrument. This instrument is
operational using a standard 9 volt battery. Change the battery only after detaching the gene gun from the
helium hose.
Refer to Requirements for System Operation in Section 2 for a description of the battery required for the
gene gun and to Inserting the Battery into the Helios Gene Gun in Section 4 for information on replacing the
battery in the instrument.
Ear and Eye Protection
Caution: Expansion of gas from high-pressure to low-pressure produces a sound wave, the intensity of
which is a function of the gas pressure. The intensity of the sound generated by discharging the Helios Gene
Gun is ~108 decibels (db) at 400 psi; sustained noise levels of 85 db or brief noise levels of 110 db may lead
to permanent hearing damage. Hearing protection should be worn by all those in the immediate vicinity
when discharging the Helios Gene Gun. Earmuffs or ear plugs provide equivalent protection against hearing
damage. Refer to Requirements for System Operation in Section 2 for suggestions on ear protection.
Eye protection should always be worn when working with gases under high pressure.
Fig. 1. Location of the instrument serial number label on the Helios Gene Gun.
Serial number lablel

Section 2 Introduction to Particle Delivery
Helios Gene Gun System | 3
Section 2
Introduction to Particle Delivery
Particle Delivery Technology
Particle bombardment is a physical method of cell transformation in which high-density subcellular sized
particles are accelerated to high velocity to carry DNA into cells. The technique was first described as a
method of gene transfer into plants (Klein et al.1987, 1988; McCabe et al.1988) and subsequently shown
to be applicable to mammalian experimental systems (Zelenin et al. 1989; Yang et al.1990; Williams et
al.1991). Because it does not depend on specific ligand receptors and/or the biochemical features of
structural components typically present on cell surfaces, particle-mediated gene transfer can be readily
applied to a variety of biological systems. Consequently, this procedure can be used to transform such
diverse targets as bacteria (Shark et al.1991; Smith et al.1992), fungi (Armaleo et al.1990), and intracellular
organelles (Johnston et al.1988; Boynton et al.1988). Since it is a physical method of gene delivery, particle
bombardment also overcomes physical barriers to effective gene transfer, such as the stratum corneum of
the epidermis and the cell walls of plants. Particle bombardment is a convenient method for transforming
intact cells in culture since minimal pre- or postbombardment manipulation is necessary. In addition, this
technique is much easier and faster to perform than the tedious task of microinjection. Both transient and
stable expression are possible with particle bombardment. In addition to DNA, RNA may also be transferred
to cells by particle bombardment (Qiu, et al.1996). Table 1 lists some of the advantages of using particle
bombardment for in vitro and in vivo transformation.
Table 1. Advantages of particle bombardment for in vitro and in vivo gene transfer.
■ Easy to use, rapid, and versatile gene delivery system
■ Works with any target cell type
■ Useful for both transient and stable expression
■ Requires only small amounts of DNA
■ No carrier DNA is needed
■ Requires only small numbers of cells
■ May obtain high levels of cotransformation
■ Large DNA fragments may be transferred
■ Enables direct intracellular delivery to many cells in the target area
■ Applicable to both in vitro and in vivo transformation
■ No extraneous genes or proteins are delivered
The Helios Gene Gun
The Helios Gene Gun is the second instrument in Bio-Rad’s particle delivery product line. In contrast to
the PDS-1000/He System, in which the overall size of the target to be transformed is limited by the size
of the chamber, and the target tissue is subjected to a vacuum during bombardment, the Helios Gene
Gun requires no vacuum and any target accessible to the barrel can be transformed. Consequently, the
Helios Gene Gun may be used in a much wider variety of gene transfer applications and provides a tool for
both in vitro and in vivo transformations in the research lab. Essentially any type of cells that can be made
accessible to its nozzle may be transformed.

Section 2 Introduction to Particle Delivery
4 | Helios Gene Gun System
In vertebrates, the epidermal cells of the skin are the most obvious target (Yang et al.1990, Williams et al.
1991). In vivo experimental systems have targeted the skin for vaccination studies (Tang et al.1992, Fynan
et al.1993, Eisenbraun et al.1993), wound healing studies (Andree et al.1994), and cytokine gene therapy
studies in mouse tumor models (Sun et al.1995, Keller et al.1996, Rakhmilevich et al.1996). In addition to
skin, muscle and internal organs, including liver, pancreas, spleen, kidney, etc., when appropriately exposed
surgically, can also be targeted in vivo (Yang et al.1990, William et al.1991, Cheng et al.1993). Using the
Accell Gene Gun, both primary and established cultures of mammalian cells have been transfected in
vitro and ex vivo (Albertini et al.1996, Mahvi et al.1996, Rakhmilevich et al.1996). Additionally, transgenic
expression of b-galactosidase, luciferase, IL-12, granulocyte macrophage colony–stimulating factor and a
nuclear papillomavirus protein has been demonstrated following in vivo transformation (Sundaram et al.
1996, Keller et al.1996, Rakhmilevich et al.1996). Meristematic tissues and leaves are obvious target cells
for in vivo transformation of plants.
Operating Principle of the Helios Gene Gun System
The Helios Gene Gun System consists of all of the components needed to prepare DNA-coated
microcarriers, coat the DNA-microcarrier suspension onto the inner surface of the GoldCoat Tubing, cut the
tubing into cartridges, which are used in the Helios Gene Gun, and finally propel the microcarriers and their
associated DNA into cells.
Prior to transfection, the plasmid DNA must be attached to the gold particles. This is accomplished by
precipitation of the DNA from solution in the presence of gold microcarriers and the polycation spermidine
by the addition of CaCl2. The particles are then washed extensively with ethanol to remove the water and
resuspended in ethanol. Using the Tubing Prep Station, the DNA/microcarrier solution is coated onto the
inner wall of GoldCoat Tubing and dried. The tubing is then cut into 0.5" length cartridges using the Tubing
Cutter. These cartridges, when inserted into the cartridge holder of the Helios Gene Gun, are the source of
the DNA that is propelled into the target cells by the helium discharge.

Section 2 Introduction to Particle Delivery
Helios Gene Gun System | 5
The Helios Gene Gun employs a high-velocity stream of helium to accelerate gold particles coated with
plasmids or RNA to velocities sufficient to penetrate and transform cells, both in vitro and in vivo (Figure
2). The discharge is initiated by pressing the trigger button, which activates the main valve, causing helium
to travel down the bore of the particle delivery device. When the helium enters one of the bores of the
cylinder containing the cartridge, the gold particles on the inside of the tubing are pulled from the surface,
become entrained in the helium stream, and begin to pick up speed. Immediately past the acceleration
channel, the barrel begins to open as a cone. The slope of the cone causes the gas to be pulled outward,
a process known as the Coanda effect (Reba 1966), expanding the high-pressure jet into a less destructive
low-velocity pulse while the gold particles maintain a high velocity. The expansion also helps spread the
microcarriers from their original 1/16" diameter to an area approximately 1/2" in diameter at the target site.
Helium
Cartridge holder
O-rings Barrel liner
Spacer
Acceleration channel
Cartridge with DNA
coated microcarriers
Fig. 2. How the samples are delivered. Helium gas is pulsed through the cartridge loaded with DNA-coated microcarriers. This pulse sweeps the
microcarriers from the inside wall of the cartridge. As the microcarriers enter the barrel liner they pick up speed in the acceleration channel then
spread out as they travel down the barrel. The increased cross-sectional area of the barrel from the acceleration chamber to the spacer also moderates
the helium shock wave so it is less intense when it reaches the target cells. The O-rings on each side of the cartridge holder direct the flow of helium
through the cartridge and the acceleration channel. The spacer maintains optimal target distance and permits venting of the helium gas away from
the target.
Requirements for System Operation
Selecting a Site for Operation
The Helios Gene Gun is a portable particle bombardment device. The range of its use is limited by its
requirement for a supply of pressurized helium and the 6 foot length of pressurized helium hose. When using
the Gene Gun, only a small area is needed for setting down the gun during an experiment, for loading the
cartridges into the cartridge holders, and for exchanging cartridge holders during experiments. In addition, a
clean and dry area is needed for working with the tissue samples.
Preparation of the gold/DNA tubes used in the gene gun requires an area approximately 1 m2for the Tubing
Prep Station and for manipulating the tubing, precipitating the DNA onto the gold, and processing the tubing
into cartridges. Additionally, the Tubing Prep Station requires an electrical outlet and a tank of pressurized
nitrogen for evaporating the ethanol from the DNA-coated gold particles from the inner surface of the tubing.

Section 2 Introduction to Particle Delivery
6 | Helios Gene Gun System
User Supplied Components
Helium Supply
Only helium gas is to be used with the Helios Gene Gun. The low atomic weight of helium results in
maximum gas expansion when the high-pressure helium is released through the valve opening and enters
the cartridge at atmospheric pressure. Thus, sufficient acceleration of the DNA-coated microcarriers is
generated for penetration of the target cell membrane.
Compressed helium of grade 4.5 (99.995%) or higher should be used; lower grades may contain
contaminating material, which can obstruct gas flow within the Helios Gene Gun as well as contaminate the
biological sample. A helium tank pressurized to 2,600 psi (approximately 5 ft (1.7 m) high, 291 cu ft standard
in the U.S.) is recommended, although a smaller tank (~2.5 ft (~0.8 m) high) may be used. Follow all safety
instructions provided by the helium supplier for helium tank installation.
The helium pressure regulator (supplied) has a CGA 580 female fitting (standard in the U.S.) for attachment
to the user-supplied helium tank. An adaptor to this fitting may be required outside of the U.S. Contact
your local Bio-Rad office for information on the helium pressure regulator adaptor requirements in your
location. The regulator supplied with the Helios Gene Gun is the only one that should be used with this
instrument because of its three safety features: (1) a self-venting valve that permits decreasing the pressure
in the Helios Gene Gun System in the event of battery failure or when it is necessary to reduce the pressure
during an experiment; (2) an over-pressure relief valve that prevents the helium pressure in the Helios Gene
Gun System from being adjusted above 700 psi ± 10%; and (3) a check valve that shuts off pressure if the
helium hose is disconnected while the system is still pressurized (Note: a check valve is also present at the
female connector of the helium hose where it connects to the gene gun to shut off pressure to the gun if it
is disconnected while the system is still pressurized.) Refer to Connecting the Helios Gene Gun to a Helium
in Section 4 for proper use of the helium regulator and to Removing Used Cartridges, Depressurization, and
Shutdown in Section 5 for a description on shutting down the gene gun system.
A user supplied 10" or 12" (~25 cm) adjustable wrench or a 1 1/8" open end wrench is required for attaching
the helium regulator to the helium tank.
Nitrogen Supply
Compressed nitrogen of grade 4.8 (99.998%) or higher is required for cartridge preparation using the Tubing
Prep Station. Nitrogen is used for this purpose because it is relatively inexpensive and provides a water-free
atmosphere for evaporating the ethanol from the DNA/gold sample inside the tubing. As with the helium
tank, the nitrogen tank should be properly secured on a floor stand or with a strap for safety.
A nitrogen regulator must be attached to the tank. A single-stage regulator with an output gauge that
registers a maximum of 30 psi is recommended since an output pressure of no more than 1–2 psi is needed
to produce the 0.4 liters per minute (LPM) flow rate necessary for using the Tubing Prep Station. A regulator
especially designed for this use, including a self-venting valve, an over-pressure relief valve, and a hose barb
for attaching the nitrogen hose, is available from Bio-Rad (#1652425). Other regulators that are adjustable
to give a low pressure output may also be used. Manufacturers of regulators include Victor and Matheson;
examples of regulators that may be used include Victor Model No. SR250A-580 and Matheson Model No.
3537-580. Large scientific supply houses (for example, VWR, Fisher Scientific, CMS, etc.) are also good
sources for regulators. The nitrogen line provided for use with the Cartridge Prep Unit is 3/16" diameter
Tygon Tubing.

Section 2 Introduction to Particle Delivery
Helios Gene Gun System | 7
Battery
One battery is provided with the Helios Gene Gun System. Under normal use, it should provide
approximately 1,000 discharges. For maximum life, use only alkaline batteries.
Laboratory Equipment
The following materials should be available before beginning any work with the Helios System.
■ Ultrasonic cleaner (for example, Fisher FS3, Branson 1210)
■ Vortex mixer
■ Analytical balance
■ Microcentrifuge
■ Peristaltic pump capable of pumping 5–8 ml/min
■ 1.5 ml microcentrifuge tubes
■ 20, 200, and 1,000 µl micropipettors and tips
■ 5 and 10 ml pipets and pipettors
■ Lab timer
■ Ear protection (for example, VWR catalog number 56610-728 (earmuffs) or 56610-680 (ear plugs)
■ One 1/8" open end or 10" or 12" (~25 cm) adjustable wrench
■ Helium tank (grade 4.5 or higher)
■ Nitrogen tank (grade 4.8 or higher)
■ Nitrogen regulator (for example, Bio-Rad, #1652425)
■ Scissors
■ Marking pen
Laboratory reagents
The following chemicals will be needed for coating plasmid onto the gold and for preparing the tubing:
■ Gold microcarriers
■ Polyvinylpyrrolidone, MW = 360,000
■ 100% ethanol (for example, Spectrum Chemical, catalog number ET-107; it is extremely important that
this be free of water; an unopened bottle should be used daily)

8 | Helios Gene Gun System
Section 3 Product Description
■ Spermidine (for example, Sigma, catalog numbers S-0266 or S-4139)
■ Calcium chloride (CaCl2)
■ Plasmid DNA (for most applications, this should be at a concentration of ~1 µg/µl)
■ Plasmid DNA of high purity suitable for the Helios Gene Gun can be obtained through use of any of
Bio-Rad’s Quantum Prep Plasmid Prep Kits. See Section 9, Product Information, on page 41.
Section 3
Product Description
Packing List
The Helios Gene Gun System (see Figures 3 and 4) is shipped with the following components. If items are
missing or damaged, contact your local Bio-Rad office.
Helios Gene Gun Kit
■ Instruction manual
■ Warranty card (please complete and return)
■ Helios Gene Gun
■ 5 cartridge holders
■ 5 barrel O-rings
■ 5 barrel liners (four plus one installed in gene gun)
■ 9 volt battery
■ Cartridge extractor tool
Helium hose assembly
Helium regulator
Tubing cutter and 10 razor blades
Tubing Prep Station (see Figure 4)
■ Tubing prep unit (base, tubing support cylinder, and power cord)
■ Nitrogen hose (12' (~4 m), Nalgene Tubing 8000-0030, 3/16" ID, 5/16" OD)
■ 3/16" barb-to-male luer fitting
■ 10 cc syringe sleeve

Helios Gene Gun System | 9
Section 3 Product Description
■ 5 O-rings, Tubing Prep Station
■ Two 1/8" barb-to-male luer fittings
■ 5/64" Allen wrench
■ Syringe Kit
− 5 10 cc syringes
− 5 1/8" barb to female luer fittings
− 1 syringe adaptor tubing (silicone, 5' (~2.6 m), 0.104" ID, 0.192" OD)
Optimization Kit
■ GoldCoat Tubing (50' (~26 m))
■ 1.6 µm gold microcarriers, 0.25 g
■ 1.0 µm gold microcarriers, 0.25 g
■ 0.6 µm gold microcarriers, 0.25 g
■ Polyvinylpyrrolidone, MW 360,000 (0.5 g)
■ 5 desiccant pellets (store tightly sealed)
■ 5 cartridge collection/storage vials
Note: If any of the system components (Helios Gene Gun, Tubing Prep Station, tubing cutter, helium
regulator, or helium hose) are dropped, check them for proper operation before use.
Fig. 3. Major components used for sample delivery with the Helios Gene Gun.
Cartridge extractor tool
Cartridge holder
Barrel liner
Helium regulator
Helium hose (6')

10 | Helios Gene Gun System
Section 3 Product Description
Fig. 4. Components of the Tubing Prep Station.
Identification of System Components and Controls
Helios Gene Gun
The locations front and back refer to the barrel end and LED display end of the Helios Gene Gun,
respectively. The locations left and right refer to the left and right sides of the Gene Gun from the viewpoint
of the user holding the device. Top and bottom refer to the side of the gun that the cartridge holder is on
and the side of the gun where the helium hose connects, respectively (see Figure 5).
Fig. 5. Components and controls on the Helios Gene Gun.
Tubing support
cylinder
O-ring
Spring
Spur gear
Tube prep unit
Syringe sleeve screw
10 cc syringe sleeve
10 cc syringe (5x)
Female luer (see detail)
Male luer (see detail)
Tubing cutter
Male and female luer detail
Nitrogen hose (12')
Syringe adaptor
tubing (5')
TOP
LED display
BACK
Safety interlock button
FRONT
Push bar
Trigger button
Cylinder advance lever
Battery access cover
Male Female

Helios Gene Gun System | 11
Section 3 Product Description
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 be
removed only 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 reactivate the trigger
button.
Trigger button Controls the flow of helium gas through the gene gun. This switch activates the solenoid, opening the main valve for
~40 msec and permitting helium to enter the cartridge and barrel. The trigger button is active for only 30 sec after the
safety interlock switch is depressed.
Cylinder advance lever A multifunctional lever that 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.
Push bar A metal bar that ratchets the cartridge holder from one position to the next when the cylinder advance ever is pressed.
Moving this bar to the left (outward) when inserting a cartridge holder provides additional room for maneuvering the
cartridge holder.
LED display An 11-light display. The display is normally off; inserting a cartridge holder in the gene gun and advancing to position 1
activates the display. The left-most 7 LEDs act to indicate charging and ready status of the gun. After each firing of the
gun and at reset, the CHARGING LEDs turn on in bar graph fashion, left to right, throughout the 5 sec charging time.
Once the gene gun is fully charged, the CHARGED LED will flash, indicating the safety interlock switch can be pressed.
On pressing the safety interlock, the ARMED LEDs flash sequentially. When the trigger is pressed during the 30 sec
armed period, the gun fires and the FIRED LED turns on for 1 sec. The change bar graph then operates as described.
The last light indicates battery status: good battery (steady green light) or low battery (flashing red light). The gene gun
can be fired when the green light is illuminated. If the battery is low, neither the safety interlock switch nor the trigger
button is active and an alarm will beep three times every 15 sec.
Tubing Prep Station
A tool for coating the DNA/microcarrier solution onto the inner wall of GoldCoat Tubing. See Figure 6.
Tubing Prep
Unit Controls Description
3-position switch Located on the motor housing and controls rotation of the tubing support cylinder. At position (I), the tubing support cylinder
turns continuously at 30 revolutions per min (rpm). At position (II), the tubing support cylinder rotates only while the switch is
depressed. At position (O), no rotation occurs and the unit is off.
Flowmeter Registers the rate of nitrogen flow in liters per min (LPM) into the tubing support cylinder. The valve on the flowmeter is used
to control the rate of nitrogen flow.
Tubing support
cylinder
A 28" aluminum cylinder with an opening on the right side leading to a channel that holds the GoldCoat Tubing. The left side
of the channel has a replaceable O-ring into which the tubing must be inserted. The tubing support cylinder can be removed
by pushing it to the right/left to compress the spring that holds it in position.

12 | Helios Gene Gun System
Section 3 Product Description
Fig. 6. Components and controls on the Tubing Prep Station, fully assembled.
Tubing Cutter
An instrument for rapid preparation of cartridges from GoldCoat Tubing. It cuts the tubing into the exact
length and shape required by the gene gun. See Figure 7.
Tubing Cutter Part Description
Arm A spring-loaded piece that holds a razor blade (used for cutting the tubing). The razor blade is held in place by the locking
knob on the lock block.
Base The support for the arm. It positions a storage vial under the tubing channels so that the cut tubing pieces fall into the vial.
Fig. 7. The tubing cutter.
Support bar
Clamp
Syringe sleeve
Tubing support cylinder
Syringe adaptor tubing
Tubing channels
Razor blade
Arm
Base
Motor housing
Syringe adaptor tubing
1/8" barb male
luer fittings
3 position switch
Flow meter
Valve
Nitrogen hose
1/8" barb female
luer fitting
To nitrogen
regulator
Spur gear
Attached to
Tefzel Tubing

Helios Gene Gun System | 13
Section 3 Product Description
Cartridge Extractor Tool
A 12-prong tool for removal of tubes from the cartridge holder. One prong is longer than the others so it can
be easily inserted into one of the bores of the cartridge holder to orient the remaining 11 prongs.
Fig. 8. Cartridge holder and cartridge extractor tool.
Cartridge holder
Cartridge extractor tool

Section 4 Inserting the Battery into the Helios Gene Gun
14 | Helios Gene Gun System
Section 4
Inserting the Battery into the Helios Gene Gun
The electrical system of the Helios Gene Gun is powered by a 9 volt battery. Under normal use, this should
provide sufficient energy for 1,000 shots. The battery compartment is in the base of the handle near the
attachment fitting for the helium hose (Figure 9).
To insert the battery, first remove the battery cover by sliding it toward the front of the gene gun. Slide
the battery into the opening as shown in Figure 9. The battery must be oriented with the positive terminal
toward the front of the gene gun, as indicated by the "+" symbol inside the battery compartment. (Note:
If the battery is inserted correctly, a tone will be audible for ~5 sec and the battery status LED will light; if
the battery is inserted backward, the electrical system will not operate and the Helios Gene Gun will be
nonoperational.) The battery is held in place by the battery cover.
Fig. 9. Battery compartment. The battery compartment is located at the base of the handle of the gene gun next to the connection for the
helium hose and is protected by a battery cover that slides forward. The battery is inserted with the positive terminal (the smaller of the two terminals)
facing forward.
TOP
LED display
BACK
Safety interlock button
Cartridge holder
Cylinder lock
Barrel liner
FRONT
Push bar
Trigger button
Cylinder advance lever
Battery access cover

Section 4 Inserting the Battery into the Helios Gene Gun
Helios Gene Gun System | 15
Connecting the Helios Gene Gun to a Helium Source
Refer to Safety Information, in Section 1, and Identification of System Components and Controls, in Section
3, prior to system installation.
Helium Pressure Regulator Installation
Components needed
■ Pressure regulator for helium cylinder (with pressure relief valve, check valve, and female Swagelok
Quick-Connect Fitting), provided with unit (Figure 10)
■ Helium cylinder of grade 4.5 or higher (minimum 99.995% pure); maximum pressure of 2,600 psi
user supplied.
■ One 1/8" open end wrench or a 10" or 12" adjustable wrench, user supplied
Note: The regulator is intended for use only with helium gas with a maximum pressure of 2,600 psi. The
outlet on pressurized helium cylinders used in the U.S. is compatible with the fitting supplied on the pressure
regulator with the Helios Gene Gun System (CGA 580, female fitting). Outside the U.S., contact your local
Bio-Rad office for information regarding the proper cylinder/regulator fitting in your area.
Procedure
1. Secure the cylinder in a floor stand or to a wall or lab bench with a strap so it will not tip or fall
during use.
2. Inspect the cylinder valve for dirt, dust, oil, grease, or damaged threads. Remove dust and dirt with a
clean cloth. Do not attach the regulator if you determine that the valve port is damaged or cannot be
cleaned. Inform your gas supplier of this condition and request a replacement cylinder.
3. Clear the valve port of any foreign matter by standing to the side of the cylinder and quickly opening and
closing the cylinder valve.
4. Attach the regulator to the cylinder valve and tighten securely with a 1 1/8" open end wrench or a
10" or 12" adjustable wrench.
Attaching the Helios Gene Gun to the Helium Regulator
Components needed
■ Helium regulator attached to a helium cylinder
■ Helium hose assembly
■ Helios Gene Gun
Procedure
1. Insert the stem of the Swagelok Quick-Connect Fitting on the helium hose into the opening in the
body of the Swagelok Quick-Connect Fitting on the helium regulator and push until it clicks. The
helium hose will be locked into the helium regulator (see Figure 10). Note: If the helium regulator has
been pressurized, the stem and body will not lock. Turning the regulator valve counterclockwise will
depressurize the system.

Section 4 Inserting the Battery into the Helios Gene Gun
16 | Helios Gene Gun System
2. In a similar manner, insert the stem of the Swagelok Quick-Connect Fitting on the Helios Gene Gun into
the opening in the body of the Swagelok Quick-Connect Fitting on the helium hose until it clicks. The
gene gun will be locked into the helium hose.
Fig. 10. Connecting the helium hose to the helium regulator.
Setting up the Tubing Prep Station
Refer to Identification of System Components and Controls, in Section 3, prior to system installation. See
Figure 11 for a diagram of the assembled Tubing Prep Station.
The Tubing Prep Station is shipped disassembled. The following sections describe assembly of the Tubing
Prep Station, attachment of the syringes and tubing, installation of the nitrogen pressure regulator, and
connection of the Tubing Prep Station to the nitrogen regulator.
A peristaltic pump is recommended for removal of the ethanol from the GoldCoat Tubing after the
microcarriers have been loaded (see Section 5.1). If a peristaltic pump is not available, you may remove the
ethanol manually using a syringe. Assembly of the syringe and tubing is described in step 5 of the following
section.
Assembly of the Tubing Prep Station and Syringes
Components needed
■ Tubing Prep Station, base
■ Tubing Prep Station, tubing support cylinder
■ Tubing Prep Station, power cord
■ O-rings, for tubing support cylinder
■ Syringe adapter tubing (silicone, 5', 0.104" ID, 0.192" OD)
Connection to helium tank
Sleeve
Stem
Connection to gene gun
Female Swagelok Quick-Connect Fitting
Helium regulator
Pressure relief valve
Female Swagelok Quick-Connect
Fitting with Check Valve
Male Swagelok Quick-Connect Fitting
Helium hose (6')