Check out our list of Bactron Anaerobic Chamber frequently asked questions and answers!

Anaerobic Mixed Gas:
• What Type of Gas Should I Use With My Bactron Chamber?
* Each Bactron chamber is equipped to be used as a 2-gas system. The first gas should always be Anaerobic Mixed Gas (AMG) which is a pre-mixed combination of 90% Nitrogen, 5% Hydrogen and 5% Carbon Dioxide. The system can be run with just AMG or you have the option of hooking a second tank of 100% Nitrogen to the second gas input line. When both AMG and Nitrogen are hooked up, the Bactron will auto-cycle the first two cycles with Nitrogen only, and the third cycle with AMG; Nitrogen is more economical so the 2-gas option will save you a little money.

• How much gas does a chamber use per month?
* Usage can greatly effect how long a tank will last. However, for most labs a tank will last several months.

Catalyst:
• How Often Should I Bake Out My Catalyst?
* You should replace your used catalyst with a fresh one each day. The Bactron systems come standard with two catalysts to allow you the ability to bake-out one, while the other is in use.

• Can I leave a catalyst cartridge in over the weekend, if the chamber will not be entered until Monday morning?
* Yes.

General Questions:
• Can I use the Bactron for microaerophilic cultures?
* The Bactron chamber does not include an oxygen sensor. However, users have been successful in maintaining microaerophilic environments by using a pre-mixed gas and removing the catalyst. Please call tech service for more information 1-800-322-4897.

• Is the air lock the only means to move items in and out of the Bactron?
* No. You can also bring small items in through the gloves when you enter the chamber.

• How do I clean /disinfect the chamber surfaces?
* Only Zephrin Chloride (Benzalkonium chloride) can be
used to disinfect the interior of Bactron the chamber.

• What oxygen indicator do I use?
* Foil Wrapped Oxygen indicator strips. Make sure to always have a fresh,
moist strip.

• Is there a non-latex option for the sleeves and cuffs?
* Yes. The standard sleeves are made from Butadyl. Nytril cuffs can be ordered in small, medium and large sizes from Sheldon MFG.

• What do I do when there is an accidental oxygen exposure to the chamber?
* Purge the entire chamber as soon as possible.

• What is the purpose of Anatox and how do I use it?
* Anatox is an odor absorbent that can be placed in the
anaerobic chamber.

• What is the purpose of the overtemp alarm and how do I
adjust it?
* The over temp alarm alerts you when the incubator has
gone over your set point. You can adjust the alarm by
using a coin to turn the knob clockwise. For setting
instructions, please refer to your Bactron user’s manual.

• How often do I have to replace bactron sleeves and cuffs?
* Usage will greatly affect how long these parts will last. In
general both the cuffs and sleeves will last approximately
six months. However, cuffs come in different sizes and
may need to be switched out for each user depending on
user comfort.

Trouble Shooting:
• My Pressure System is Injecting Too Often.
* There is probably a leak in the glove box work area, check
the following places using a leak detector:
-Around Plexiglas
-Armport Doors
-Pass Through Box Door
-Manometer
-Proximity Switch on Pass Through Box Door
-Chiller
-Incubator Door (Bactron IV Models Only)
-Pressure Switch
-Swivel Elbow

• My Vacuum Pump Keeps Running.
* You have a leak in your vacuum system. Here are some
places to check for leaks:
-Check the valve, Vacuum Solenoid, Foot Pedal & Vacuum Switch – These are the most common places that you would find a vacuum leak.
-Check the tubing that plugs into the small vacuum elbow
-Check the proximity switch

• My Chamber Keeps Fogging Up.
* Replace the dehumidification component (Chiller)

Perhaps no where better than in a laboratory does the old axiom apply that the better tool you have, the better job you can perform. And the better the results will be. Laboratory equipment, particularly controlled temperature equipment, must help ensure that the environment in which specimens or cell cultures are being studied is safe and contaminant-free, and that, above all, study results are reliable.

CO2 incubators are a popular choice

One of the essential pieces of controlled temperature equipment in any laboratory is an incubator. These days, the CO2 incubator is among the most prevalent type. In most laboratories, technicians mainly are growing or sustaining mammalian cells. CO2 incubators are intended for tissue and cell culture applications. These incubators work on three building blocks: carbon dioxide (CO2) temperature and relative humidity (RH). The laboratory technician or scientist using a CO2 incubator is trying to replicate the mammalian environment (in-vivo), outside (in-vitro) of its natural state. The incubator allows these elements to work together to create an ambient environment for cells to thrive. The result is a balanced controlled pH (7.2 - 7.4); stable temperature - 37 C; high relative humidity - 95%; and controlled CO2 level - 5%.

Air-jacket vs. water-jacket: both offer benefits

The water-jacketed CO2 incubator envelopes the unit’s chamber, providing superior insulation while eliminating contamination tamination and cold spots. In addition, the water-jacket is surrounded by insulation, which makes the incubator ideal for maintaining precise conditions. 1bese essential conditions are why water-jacketechnology was first invented and remains the standard in tissue/cell culture today.

Similar to the water-jacketed incubator, an air-jacket CO2 incubator has a heated inner chamber that is controlled by sophisticated microprocessors. These microprocessors constantly monitor and adjust program settings and allow calibrations of CO2 and temperature. As a result, condensation on the inner glass door and back chamber wall is minimized.

For both types of incubators, the microcomputer controls include backup systems that prevent samples from overheating, plus alarms that monitor the out-of-tolerance conditions. Both air-jacketed or water-jacketed incubators will provide a controlled atmosphere for samples.

Copper deters contamination

In the challenge to eliminate contamination in incubators, whether they are air- or water-jacketed, some manufacturers have incorporated copper into the chamber design. As copper breaks down, it releases copper oxide, which destroys any microbes present in the chamber. Some incubator manufacturers offer copper shelves or a copper interior. Sheldon Manufacturing has taken still a different approach by designing copper into the housing that surrounds its High Efficiency Particulate Air Filtration System (HEPA). This patented feature destroys trapped particulates and eliminates contamination where it affects the incubator the most in the chamber air. Copper also is extensively used in the CO2 line, water-jacket and sample port, again, to reduce the possibility of foreign bacteria contamination.

Sizes of CO2 incubators

Once an incubator style is chosen, size becomes the next major consideration given the typically space-restricted condition of most laboratories. Personal air and water jacket incubators, for example, offer compact size, conserving valuable lab bench space, and are excellent for microbiological and cell culture research. At the other end of the spectrum, large CO2 incubators and floor models are ideal for large volume incubation of valuable cells, tissues and cultures. The use of various apparatus inside the chamber, such as roller bottle systems and cell harvesters, is common. These incubators can range in capacity up to 60 cubic feet.

Type of CO2 Controls

To maintain the chamber environment for safe and reliable research, today’s CO2 incubators are equipped with precise automated controls. There are two primary types of controllers offered on CO2 incubators: Thermal Conductivity (TC) and Infrared (IR). The IR sensor is to date the most sophisticated technology for CO2 detection and control. It uses an infrared sensor to detect a change in CO2 concentrations as little as 0.1 %. Since the IR sensor is unaffected by changes in temperature and humidity, it is ideal for applications in which the incubator door is frequently opened, and provides nearly perfect culturing conditions for cell growth. The sensor continuously samples chamber atmosphere through a spectrophotometer flow cell, checking wavelength and instantly correcting an out-of-control condition. Also, CO2 recovery is rapid and changes in CO2 concentration are made within seconds.

The Thermal Conductivity (TC) Sensor is a more indirect method of CO2 detection and control since it measures the level of CO2 by sensing temperature differences as CO2 is introduced into the chamber.

General-purpose incubators offer alternative
If CO2 is not a pre-requisite for incubator selection. then general-purpose incubators may be best. Applications of these systems include biochemical, bacteriology, and hematological studies. These units are offered in air-jacket or waterjacket options, in sizes from bench to floor models, and in economy styles with analog controls.

Water-jacketed general-purpose incubators are specified when ambient temperatures in the laboratory fluctuate. and for high humidity applications. Incubator models are offered with different types of controllers, sizes, and types of construction.

The majority of units are air-jacketed models. Some suppliers offer gravity convection and convection or forced-air incubators. Gravity units rely on the principle that warm air rises. and have no fans or blowers. Convection units are equipped with a fan to move or circulate the warm air to enhance temperature uniformity. Unfortunately. in most convection units the fan also causes a negative side effect drying of samples.

Sheldon Manufacturing offers both gravity-based units and a unique convection style incubator that has a triple wall. The triple-wall construction offers five heaters and a fan located outside the chamber to enhance temperature uniformity, without the common problem of drying samples.

Floor model incubators ideal for high volume applications

Floor model incubators are used for high volume applications when apparatus is used inside the controlled temperature atmosphere. An electrical outlet is provided inside the chamber. In addition. a prewired chart recorder panel is provided to the right of the control panel to produce a hard copy of test results.

Incubators for special low temp/B.O.D. application

A full line of incubators equipped with both heating and cooling capabilities can be obtained for a broad range of applications. These units are ideal for fish and insect work. Units are commonly operated close to ambient conditions, making refrigeration necessary. Also, many lab technicians do not want to work in a cold room environment and will choose an incubator for storing samples instead. Another use for these units is biological oxygen demand (8.0.0.) determinations, A.P.H.A. tests, serum studies and enzyme assays. It is important that units have safety features for both high limits and low limits.

Some tests may require diurnal growth chamber

The Diurnal Growth Chamber has both heating and refrigeration capabilities, plus a programmable light system. The unit can duplicate day/night growth testing, stability testing, and seed gennination. Two 24-hour timers independently control temperatures and lighting in 15-minute increments, simulating a diurnal cycle. A typical cycle could be an 8-hour day (heat and light), and a 16-hour night (cold and dark).

Anaerobic chamber saves money, turnaround time

Another entirely unique and different type of incubator is one designed for laboratories that are studying, or wish to study, anaerobes (life fonns in the absence of molecular oxygen). There are anaerobic chambers with built-in incubators available. These chambers enable lab technicians and scientists to conduct research in a strictly anaerobic environment, which is essential for reliable research results that could ultimately link anaerobes to certain infections leading to human diseases. In fact, research and clinical laboratories performing even a limited number of anaerobic procedures save substantial amounts of money by using permanent systems rather than disposable pouches and jars. It is of equal importance that anaerobic chambers can cut up to 50% in turnaround time given their ease of use and efficient operability.

An anaerobic environmental chamber is designed to allow efficient and dexterous glove-free handling and inspection of samples. Modular systems within the chamber facilitate the completion of procedures from unpacking material to inoculation, incubation, inspection and recovery, all without a single exposure to oxygen.

The handling of specimens required for anaerobic study must be done carefully and delicately. For this reason, convenience in the way the chamber is designed for operation by the technician is paramount.
Sheldon Manufacturing offers in its Bactron line of anaerobic chambers a special patented cuff that permits the technician to work barehanded inside the chamber without compromising the oxygen-free atmosphere. This enables the technician to bring small items into the chamber through the glove-free sleeve system. The result is greatly increased operator comfort and significantly improved productivity.

Choosing the best incubator for today’s laboratory is a process that has been significantly helped by a large variety of equipment catering to differing applications, chamber capacity needs, and ease of sample study. Depending upon the application, having the right controlled temperature equipment will greatly enhance efficiency, increase productivity, and give substantial savings over manual disposable methods.

Originally Published in Biomedical Products 2002

The new SHEL LAB Incubator Shaker literature is now available online. This four page brochure highlights the full line of SHEL LAB Shaking Incubators including the High Speed SI6R-HS (up to 850 RPM’s) and the SI9 Large Capacity Incubator Shaker. Download the SHEL LAB Incubator Shaker Brochure

In the ideal laboratory setting, transferring cell growth samples in and out of incubators would be done without concern about contamination and its potential effect on samples. But until environmental control equipment creates this perfect environment, monitoring contamination and ensuring a clean test environment is critical. There are two ways to accomplish this: 1) select an incubator, preferably a CO2 incubator, that has design features that will help to keep contamination at an almost nonexistent level; and 2) follow a cleaning procedure that is thorough and performed on a regular basis.

Cleaning is particularly important because it can mean the difference between a high-quality, reliable analysis and one that is faulty. Anyone working in a laboratory environment using this kind of equipment wants to avoid inaccurate scientific conclusions.

Fortunately, with the development of CO2 incubators, there is a cleaner and safer testing environment within the incubator itself. This has helped keep contamination in check for the most part. although incubator disassembly and cleaning is still critical. Technicians, scientists, or researchers using CO2 incubators are growing or sustaining mammalian cells. Any application will require time for testing and study. CO2 incubators are intended for long-term tissue and cell culture applications. Their advanced design controls contamination.

Why are CO2 incubators an important consideration in conjunction with cell culture analysis? A CO2 incubator operates on fairly simple parameters based on three elements: carbon dioxide (CO2), temperature, and relative humidity (RH). A scientist using a CO2 incubator is trying to reproduce the mammalian environment (in vivo) outside of its natural state (in vitro). Therefore, the incubator combines three elements that create an environment needed for cells to thrive by establishing a balanced and controlled pH at 7.2-7.4: stable temperature at 37 °C, high RH at 95%, and controlled CO2 level at 5%.

CO2 incubators have become acceptable, reliable equipment given the growth in cell culture research and the ability of incubators to grow cells in vitro. But on the flip side of this benefit is the constant threat of contamination to the cell culture environment. Therefore, it will be helpful to look at the different types of CO2 incubators available to laboratory personnel, what kinds of contamination they each can produce, and the proper regimen to follow for cleaning these incubators to decontaminate them as effectively as possible.

CO2 water-jacketed incubators

Water-jacketed incubators are designed and used primarily for in vitro incubation of valuable cells, tissues, and organisms. The water jacket envelops the incubator chamber or cabinet providing excellent insulation while eliminating prime targets of condensation. The result is that the water-jacketed incubator reduces cold spots, virtually eliminating condensation so contamination is less likely to occur. Like its counterpart, the air-jacketed incubator typically has temperature control settings (main chamber, external door, and front liner) to minimize condensation and yield precise temperature uniformity. It is a matter of personal choice for the user whether or not to choose a water jacketed or air-jacketed incubator. Both styles can provide chamber features that provide uniform temperature control, reduce condensation, and safeguard them from contamination.

Copper fights contamination

Some CO2 incubators incorporate copper in their cabinet design to deter contamination. As the copper breaks down, it releases copper oxide, which destroys microbes present in the chamber. Sheldon Manufacturing, Inc. (Cornelius, OR), produces incubators that feature a copper housing around a HEPA (high efficiency particulate air) f1ltration system filter inside the cabinet. This copper housing is patented and helps to eliminate contamination where it strikes hardest-in the chamber atmosphere. Also, replacement of the filter is easy and inexpensive. Copper is also used inside the water jacket to eliminate contamination growth over time inside the jacket. No chemicals are recommended or needed in the water jacket. Copper is also used around the sample port and the gas injection tube.

Numerous contamination sources
Humidified CO2 incubators, by their very nature, are a haven for contamination since they create an environment for the support and growth of bacteria, mold, and spores. While it may seem conflicting to have an incubator that is designed for cell culture study yet can create a decontaminated environment at the same time, the solution is to keep the chamber and all of it parts clean. One main source of contamination in humidified incubators is the humidity pan itself, an easy part to forget to clean unless the user is about to replace the water that has evaporated. Unless this is cleaned regularly, mold, bacteria, and yeast can settle in comfortably. It is also key to clean the humidity pan to maintain a constant humidity level since the humidified environment occurs only when water from the pan evaporates. The surface tension of the water is needed for a constant environment; otherwise, contamination can occur.

Contamination can develop in plastic tubing leading into the chamber, as well as in rubber gaskets that encase the incubator’s opening where mold can develop. It is important to clean out the threads or tracks of the gaskets. Sheldon’s incubators feature autoclavable and removal gaskets for easy cleaning and changing. Other trouble spots where contamination can settle include shelves, seams, and electrical cord ports that need to be part of a routine cleaning regimen.

No substitute for cleaning
As emphasized earlier, cleaning the CO2 incubator is essential, particularly for the researcher dealing with tissue culture applications. It is the only way to truly prevent contamination, and it is the best way to reliably grow cells in culture. A typical decontamination procedure that is adequate for most CO2 incubators includes:

I. Remove the humidity pan weekly and autoclave all stainless steel parts. Wash with soap and water and allow to dry. Use a disinfectant as appropriate for the application. Replace the pan in the incubator with fresh distilled water.

2. Remove all shelves, shelf supports, shelf standards, and shields. Autoclave or wash and disinfect as described above for the humidity pan.

3. Wipe down the chamber with soap and water. Allow to dry. Use disinfectant as appropriate for the application. Let dry.

4. Clean and disinfect all access ports, air bleeds, shaft holes, electrical pass-through. and any other passages into the incubator. Carefully clean around the incubator’s sensors to prevent damage.

5. Remove the door gasket and gasket guards. Clean and disinfect. Eventually, the gaskets can be replaced as they wear.

6. Replace all air and CO2 filters as needed, approximately every six months or when noticeably dirty.

CO2 filters are located on the gas inlet and inside on the circulation system. Whatever cleaning process is performed, the incubator should be cleaned and decontaminated regularly. Depending on usage and protocol, this may be weekly, monthly, or quarterly. By maintaining and cleaning the incubator, the valuable research conducted will always meet the highest standards and produce safe, reliable results.

The goal is clear: maximize patient care and minimize cost. The solution is defined: Replace expensive consumables with efficient, reliable equipment. The Result is proven: More reliable test results, lower dollar per specimen and higher quality care. Download the published article (PDF) for the complete analysis.