Most biological and life science laboratories have long relied on incubators to breed or develop insects, maintain or grow biological cultures, and replicate germ colonies. Researchers can duplicate exact temperature conditions for the best growth, development, and/or maintenance of finicky cells using even the most basic incubators. As temperature variations in the living environment might be fatal, temperature homogeneity is also essential.

The need for higher-precision incubators has grown as the fields of biotechnology and biopharmaceuticals have developed. Regulations pertaining to good laboratory and manufacturing procedures (GLP and GMP) have also been improved upon and strengthened. This has led to the development of more sophisticated cell culture control and monitoring systems, among other things. 

Practically speaking, sometimes, many labs are searching for inexpensive choices that do not affect the outcomes of their investigations. However, depending on the scientist and the intended application of the product, some specific qualities of a CO2 incubator may be sought. Some general things should be taken into account while examining the physical characteristics of a CO2 incubator and the portable co2 monitor to get accurate results. 

Let’s have a look - 

 

Size: This takes into account the internal volume, which is crucial to how much an incubator can house. Due to the limited space an incubator has, the footprint is especially important in many labs. Height can be important as well, particularly if the incubator will be placed on a countertop.

Shelving: How many samples can be stored depends on how the incubator's shelves are set up and how easily they can be moved around.

Surface: A variety of materials are usable inside. Stainless steel is a wonderful option since it reduces cleaning time and prevents corrosion. Aluminum might be preferable in terms of price. A copper liner is preferred by some labs because it can lower the possibility of contamination.

Air Flow: Gravity convection can be depended upon to move air in incubators that are less expensive. A fan is necessary to maintain the incubator's temperature more consistently. An incubator may additionally have a HEPA filter for incoming air filtration.

Controls: Depending on how an incubator will be utilized, a certain level of control is required. Analog controls can reduce costs if the accuracy of interior conditions, such as temperature, is not particularly sensitive in an application. Digital controls, and even a computer link, function better for more accuracy and setting up conditions in sequences.

 

Do I Need CO2 Control?

Incubators typically regulate the internal humidity and temperature according to user-specified parameters. Controlling carbon dioxide (CO2) to a level of about 5% is another typical trait. Two factors make this significant: A crucial pH buffer, 5 percent CO2 closely mimics the natural conditions that cells would encounter throughout bodily systems. In fact, the pH levels within cultivated cells are so crucial that the majority of cell culture media include indicators so that workers may quickly see potentially harmful pH changes. Researchers are interested in finding findings that are most applicable to a living creature despite the fact that animal cells in culture have been separated from their bigger biological "host" (the organ).

Therefore, it is crucial to manipulate as many variables as you can in order to replicate these situations. For the best culture growth, certain biological labs operating with bacteria like E. coli or single-celled eukaryotic cells like S. cerevisiae do not need carbon dioxide management. As a result, these labs frequently choose cheaper incubators that just regulate temperature and humidity. However, the answer to the question "do I require CO2 control?" is unquestionably "yes" if your lab is cultivating animal cells or tissues.

 

Controlling CO2 Levels: Thermal Conductivity or Infrared?

 

Typically, CO2 incubators allow you to specify the set-point for the carbon dioxide level (generally 5 percent ). Thermal conductivity and infrared detectors are the two types that are most frequently used to track carbon dioxide levels in incubators.

Sensors that monitor thermal conductivity track changes in temperature resistance. Thermal conductivity sensors are not completely accurate since incubator temperature settings and humidity levels can influence them; this is especially true when incubator doors are opened frequently. In addition to CO2 loss, the relative humidity level decreases when a door is left open. Therefore, incubators that monitor thermal conductivity are more suitable for keeping cell cultures for a longer period of time.

Infrared is a more precise (but more costly) CO2-level monitoring technology. The amount of carbon dioxide in the incubator is determined by an optical sensor that measures light absorption in the infrared spectrum; the degree of absorption is inversely proportionate to the amount of CO2. The absorption is a more accurate CO2 concentration indication than thermal-conductivity sensors since it is unaffected by temperature or humidity. 

Most commonly asked questions

 

Does the location of the sensors in a CO2 incubator affect my cultured cells?

Yes. The same circumstances that your sensitive cells are exposed to should be applied to sensors. Some CO2 incubators include sensors outside the chamber, which causes a reaction delay and might not accurately reflect the situation right now. The hot, muggy, and slightly acidic conditions inside the chamber, however, are not exposed to external sensors, and they are also not required to endure high-temperature sterilization or chemical disinfectants.

Inside the chamber used to incubate cells, proper scientific CO2 incubators have sensors for temperature, CO2, O2, and humidity. In such a case, the sensors can respond to the same circumstances as the cells, give precise and prompt responses, reduce delays, and do away with the need for tubing and other supplies.

 

What is a bypass loop?

Instead of internal sensors, a bypass loop is utilized to gauge the conditions inside an incubator. With this technique, the air is circulated from the chamber to the sensors via a filter and tubing before being pumped back into the chamber. The measured conditions might not match the circumstances within the chamber because the air needs to be heated to maintain temperature and prevent condensation. By-pass loops could also put the chamber and your cells at risk of microbial contamination. Additionally, the requirement for the heater, pump, filters, and tubing is removed. Examples include (A) a zirconium oxide O2 sensor, (B) dual-temperature probes, and (C) a thermal conductivity CO2 sensor with relative humidity adjustment.

 

Important features when selecting a CO2 incubator

It is important to check if the incubator provides an optimal growth environment, contamination control, and enhanced simplicity. Look for the following as well-

Chamber capacityHeating method (direct or water jacketed)Sensors, filters, and other condition-monitoring options and alarmsDimensions and space limitations (this will include stackability, door swing direction)Internal configuration (adjustable shelves, glass viewing door)Construction materials (stainless-steel or copper interiors)Ease of operation, cleaning, and maintenance