Carbon dioxide (CO2) sensors are used by scientists and researchers as part of their studies into cellular growth and to measure respiration in both patients and athletes. In each case, measuring accurate CO2 levels over time is critical for success.
CO2 Sensors for Cell Culture Incubators
Cell culture incubators are designed to provide the optimum environment to promote cell culture growth. For living cell cultures this means the incubator has several variables that must be maintained:
- Temperature at 98.6°F (37°C) for human cells
- Humidity between 90 and 95%
- pH Level of 7.4-7.5 (neutral)
Maintaining each of these variables is critical for cell culture growth.
What is often a challenge, however, is maintaining the proper temperature, humidity and pH levels all at once. For example, simply opening of the incubator door can allow the humidity levels to fall or present a potential point in contamination if other substances gain entry.
Why Are CO2 Sensors Used in Cell Culture Incubators?
While we are familiar with monitoring carbon dioxide (CO2) levels around 400ppm in indoor air environments, life science applications need to monitor much higher concentrations in cell culture incubators. Depending on the application, this can be as high as 5-10% depending on the culture being grown.
Carbon dioxide at higher than atmospheric levels reacts with water to become carbonic acid or bicarbonate. This process is mimicked inside the body, which regulates the pH level using a transfer of hydrogen ions between these 2 molecules to stabilize the pH level between 7.4 and 7.5.
Research has shown that a 5% CO2 gas level inside a cell culture incubator at 90-95% humidity results in a pH neutral environment, best for cell culture growth.
Note that 5% CO2 is the equivalent of 50,000ppm. This is not only much higher than the 400ppm CO2 level in ambient air, but is dangerous. For this reason, labs that use tanks of CO2 with cell culture incubators will also have a high CO2 level safety alarm installed.
Monitoring and Maintaining CO2 Levels in Incubators
In incubation applications, consistent carbon dioxide levels throughout the incubator must be controlled. In addition to temperature and humidity, the air inside an incubator must be continuously mixed either by a fan or by convection. Since CO2 is typically added via an outside tube from a CO2 tank regulator, properly mixed air is critical to maintain an overall constant pH across the samples. This makes a reliable CO2 sensor inside the incubator a requirement for success.
CO2 Sensor Requirements
There are several challenges when using a CO2 sensor inside a cell incubator. The sensor must be impervious to high-heat sterilization, it must automatically compensate for changes in temperature, pressure and humidity, and it must be accurate without requiring factory calibration.
One sensor designed to meet these requirements is the MicroSENS IR Incubator 0-20% CO2 Sensor. This sensor has been optimized to measure 5% by volume of CO2 in cell incubators to manage ideal cell and tissue growth, as well as provide temperature and relative humidity data to the end user.
Unlike typical incubator CO2 sensors that utilize NDIR sensing, the MH-100 has an innovative design which is resistant to heat and moisture, while monitoring with Infrared dual beam sensing. This not only provides higher accuracy but also a longer life-span for the analyzer.
Benefits include:
- Clean in Place – heat sterilizable to 190C. This results in less cleaning effort, shorter sterilization time and less risk of cross contamination.
- Simple Field Calibration to meet any protocol requirement from 0-20% CO2 and at 20-60C to provide high measurement accuracy.
- Integrated Temperature and Pressure Compensation provides reliable CO2 measurements across a wide range of conditions.
- Humidity Correction provides stable CO2 levels without the influence of humidity fluctuations.
- Constructed to Pharma + Lab Standards for long-life and easy maintenance and cleaning.
- Long-Life Dual-beam NDIR Sensor is rated for 10 years of trouble-free use.
CO2 Sensors for Patient Care, Health Studies
For hospitals or researchers that need to measure exhaled breath, a fast CO2 sensor that can measure minute changes in carbon dioxide levels in real-time. New diagnostic requirements are driving the need for improvements in CO₂ waveform morphology.
While inhaled (fresh) air contains approximately 400ppm of CO2, exhaled breath contains 3-5% CO2 or about 100 times the amount. This flushing out of CO2 allows more oxygen to enter the body. Too much or too little CO2 in exhaled air is an indication of poor cellular respiration.
CO2 Sensor Requirements
To facilitate the measurement of CO2, the latest medical devices and life science researchers use CO2 sensors like the GSS SprintIR®-6S 20% CO2 Sensor. This sensor has several benefits for measuring respiration:
- Ability to measure CO2 levels up to 20 times per second
- 2.8ml sample volume of gas required to record change in CO2 levels
- Compatible with pumped gas applications
For researchers dedicated to understanding further functionality and structure around medical and healthcare advancements, the ability to see an accurate waveform at 20x per second makes incorporating such a sensor vital.
In addition, this sensor is also built on GSS patented IR LED technology which can further provide low power consumption, durability, and the option to gain real-time data analysis from our free, easy-to-use GasLab® software.
Why Choosing the Right CO2 Sensor Matters
In the ever-evolving fields of life science and bio research it is important to select the right sensing technology for your application.
If you need more information on choosing the proper CO2 sensor for your application or industry, contact us. A GasLab sensor expert will be happy to assist you.