Anaerobic chambers allow you to grow and manipulate organisms that require strict anaerobic conditions, such as many bacteria that are part of human and animal microbiomes, as well as many pathogens responsible for causing infections.

As opposed to using jars, bags, or boxes, where one needs to rush through setting up and examining plates to limit exposure to air, all steps from inoculation, incubation, inspection, and subculturing can be performed under true anaerobic conditions. For fastidious organisms that are particularly sensitive to oxygen, this is the only way to get reliable growth.

Gloved chambers have thick gloves secured to the end of each sleeve that users must slide into in order to work in the chamber.

Gloveless chambers, such as the AS-150 and AS-500, provide the ability to work in the chamber with bare hands or latex/nitrile lab gloves for better dexterity. These systems eliminate oxygen as the user enters the chamber so that the anaerobic environment is not compromised. The gloveless sleeves also have different-sized cuffs that can be easily interchanged for the comfort of different users.

The AS-500 and AS-150 chambers utilize a vacuumless passbox or airlock system, with an automatic cycle that uses a catalyst and flush cycle to remove oxygen.

A vacuum in the passbox limits the ability to bring in certain types of items into the chamber. For example, liquid in squirt bottles or spray bottles would get sucked out of the opening. Bottles of hot media right out of the autoclave could also be problematic under vacuum pressure. 

The vacuumless feature also makes the system less noisy and easier to maintain long-term, without the need to maintain or replace a vacuum pump.

The dimensions of each anaerobic chamber configuration can be found in the brochure. To speak with a Biolog representative about the logistics of placing a particular instrument or piece of equipment into a chamber, please contact sales@biolog.com.

We recommend a 3-gas mixture of anaerobic gas containing 5% CO2, 5% H2, and 90% N2. You do not need to use high purity gas; the standard gas mixture with these ratios is acceptable. The CO2 content of the gas can be increased or decreased depending on your preference. However, it is important to not exceed 5% H2 in the chamber, due to risk of explosion!

The amount of gas used will depend on the size of the chamber, and how often it is in use. Typical exchange frequency for the AS-500 is 1 tank every 10-14 days. For the AS-150 chamber, the typical frequency would be 1 tank every 14-21 days.

The passbox is typically the component that utilizes the most gas, so to conserve gas, try to bring in smaller items through the sleeves and limit use of the passbox to bringing in larger items.

The AS-500 chamber has a built-in oxygen sensor, with a read-out that can be easily monitored on the large LCD touchscreen.

For the AS-150 chamber, we recommend indicator strips, (Oxoid, BR0055), which are available commercially through Fisher Scientific. Note that these strips are very sensitive to O2 levels and will develop a light pink color at just 100 ppm. Alternately, an oxygen meter that is compatible with H2 and CO2 can be used.

When using the indicator strips, it is important that they only be opened after the chamber has not been in use for several hours, such as first thing in the morning. Open the strip inside the chamber, before bringing in anything through the airlock/passbox (the airlock will bring a small amount of O2 into the chamber). Let the strip sit in the chamber for a few minutes and make sure it stays white.

In the event of an accidental oxygen exposure, follow these steps:

1. Open the incubator doors so that there is a 1/2” gap on either side of the incubator.
2. Close the passbox doors.
3. Plug the sleeves.
4. Remove one of the screws on the front window. We recommend removing one on the right side in the middle of the window. This will create a small leak of gas out of the chamber, and fresh new gas will be added every ~5 seconds.
5. Allow the chamber to purge slowly until it has consumed 50 psi from the gas tank.
6. Place an anaerobic indicator strip inside the chamber every hour to check the oxygen level. Let the strip set for 5 minutes and check the color. If it is white or very light pink then the chamber is safe to work in again.
7. When the anaerobic environment has been restored, re-fasten the screw on the front window.
8. Close the incubator doors.

For the AS-500 chamber, the catalyst should not require any maintenance or replacement for at least 2-3 years, as it is regularly self-cleaned and runs its own diagnostic tests.

For the AS-150 chamber, at the beginning of each day, a freshly activated and cooled catalyst basket should be brought into the chamber. The old catalyst should be removed and baked to clean and regenerate it. The catalyst should be baked at a temperature greater than 160°C (320°F) for a minimum of 6 hours, but baking at a hotter temperature or longer duration is fine.

If this procedure is followed, the catalyst should only need to be replaced every 2-3 years. If the catalyst no longer heats up when exposed to air and anaerobic mixed gas at the same time, new palladium pellets should be ordered (#C100702).

Here are some tips to help you conserve gas as you work in the chamber:

Minimize passbox cycles by making sure supplies are brought inside in bulk. You can also minimize the cycles by bringing in smaller sized items like small numbers of tubes or plates through the sleeves. You do not have to worry about letting in oxygen in through the sleeves while you put plates or tubes in. The positive pressure in the chamber will ensure that the anaerobic gas is vented out through the sleeves, preventing oxygen from getting in.

Avoid bubbling excess gas out through the manometer (except when first entering the chamber). If you are going to reach deeper into the chamber where it might cause gas to bubble out, reach with one arm while pulling the other arm out to maintain the gas inside the chamber.

Always make sure the manometer is filled with 2-3 inches of water. When the manometer is too low, any small movements while in the chamber will push gas to bubble out of the manometer.

Chamber surfaces should be cleaned after every manipulation of bacterial cultures. Before exiting the chamber, use a squirt bottle and a paper towel or cleaning cloth to wipe the chamber surfaces with benzalkonium chloride (#AS-972 Chamber Cleaner). The chamber surfaces should be left damp, do not wipe dry.

On a periodic basis, Clorox Healthcare Bleach Germicidal Wipes can be used, which will eradicate C. difficile spores with a 3 minute contact time. This should not be done more than once per day. Care must be taken when using the wipes. A single wipe should be removed and then the container tightly sealed. Wipe down the surfaces, immediately dispose of the wipe into the passbox, and make sure the passbox door is sealed shut to prevent excess bleach fumes from building up inside chamber. After the specified contact time, wipe up all remaining wet spots and dispose of paper towels in the passbox.

Yes, butyl cuffs are available in small, medium, and large sizes. When ordering replacement cuffs, make sure to specify the quantity and proper size in the part number: #B08115-XX (-7S (small), -8M (medium), -9L (large)).

Anascrub is an activated carbon charcoal which removes some of the hydrogen sulfide and volatile organic acids which are by-products of bacterial growth. This helps to reduce the foul odor some of these bacteria generate, and also helps the catalyst remain active, as the need to regenerate and eventually replace the catalyst arises from hydrogen sulfide bonding to the palladium on the catalyst and deactivating it.

For the AS-500, the pellets in the filter housing should be changed about every 3 months, depending on usage. The purple potassium permanganate will change from purple, to brown, to grey, as they are consumed.

For the AS-150, we recommend placing a small stainless steel bowl or container with ~1/3 cup of pellets inside the chamber. Replace it with fresh pellets when they have changed color from purple to black and dark grey.

It depends on how heavily the chamber is used. With heavy, daily use, the cuffs should be replaced monthly. Sleeves only need to be replaced when they are worn or damaged. With proper care, they can last several years. You should always have several pairs of cuffs on hand in case of an accidental tear. It is also advised to keep a spare set of sleeves on hand. Sleeve tears (small ones) can be patched using black electrical tape.

When the humidity in the incubator is too low, moisture will evaporate from the plates and condense on the lids. We recommend keeping a beaker of water inside the incubator to maintain the humidity and prevent plates from drying out.