3 minutes for a thorough understanding of carbon dioxide incubators
The farthest distance in the world is that I will stand in front of the king to help the king study, and Jun does not know me. --CO2 incubator Do you know why cell culture is using a carbon dioxide incubator? Do you know the performance advantages of the CO2 incubator? Do you know how the current CO2 incubator can be used to help you easily achieve cell research and production? I believe that many users know that carbon dioxide incubators are a good tool for cell culture, but they know very little about how they work, their performance indicators, and how to use them correctly and efficiently. If a worker wants to do something good, he must first sharpen his tools. In the spirit of letting the kings better study the functions and metabolism of cells and the influence of cells on various environmental factors, Esco will take you into the mysterious world of carbon dioxide incubators today. 1 What is a carbon dioxide incubator A carbon dioxide incubator is a device used to culture cells/tissues in vitro by simulating a growth environment similar to cells/tissues in an organism in an incubator. The carbon dioxide incubator has more carbon dioxide concentration control system than the ordinary electric thermostat incubator, and strictly controls the temperature and humidity of the environment inside the box, such as stable CO 2 level (5%), stable temperature (37 ° C), The higher relative humidity (95%), so that the growth rate and efficiency of biological cells, tissues and the like are improved, and it is a new type of incubator which cannot be replaced by an ordinary electrothermal constant temperature incubator. 2 Why use a carbon dioxide incubator Gas is one of the necessary conditions for mammalian cell culture to survive. The required gases are mainly oxygen and carbon dioxide. Oxygen participates in the tricarboxylic acid cycle, producing the energy required to supply cell growth and proliferation and the various components required for the growth of synthetic cells. In open culture, the cells are generally placed in a mixture of 95% air plus 5% carbon dioxide. CO 2 is both a cellular metabolite and a desired component of cells, and it is mainly related to maintaining the pH of the culture solution. Most animal cells require a slightly alkaline environment with a pH of 7.2 to 7.4, and no more than 6.8 to 7.6. In the cell culture process, as the amount of CO 2 released increases, the medium becomes acidic. Therefore, NaHCO 3 is often added to the medium (H 2 CO 3 formed after the CO 2 is dissolved in water constitutes a buffer pair) To adjust the pH. NaHCO 3 has a tendency to release CO 2 , and the addition of CO 2 can inhibit the progress of this reaction. The concentration of CO 2 in the incubator should be balanced with the concentration of NaHCO 3 in the culture solution. If the CO 2 concentration in the incubator is set at 5%, the amount of NaHCO 3 added to the culture solution should be 1.97 g/L; if the CO 2 concentration is maintained At 10%, the amount of NaHCO 3 added should be 3.95 g/L. Precise control of carbon dioxide concentration is why carbon dioxide incubators are the best choice for cell or tissue culture in vitro. 3 How to achieve precise control of carbon dioxide concentration Carbon dioxide incubators commonly use thermal conductivity (TC) sensors or infrared (IR) sensors to detect changes in carbon dioxide concentration in the tank. When the door of the carbon dioxide incubator is opened, CO 2 leaks out of the tank, and the sensor detects a decrease in the concentration of CO 2 and reacts in time to re-inject CO 2 to the original preset level. . (1) Thermal Conduction (TC) Sensor The principle of thermal conductivity sensor (TC) monitoring CO 2 concentration is achieved by measuring the change in resistance between two thermistors. The change in CO 2 concentration in the tank changes the resistance between the two thermistors. The low thermal conductivity of the input CO 2 gas changes the thermal conductivity of the air in the chamber, which produces a direct proportional to the CO 2 concentration. Electrical signal. This causes the sensor to react to achieve the effect of adjusting the CO 2 level. The TC control system has certain disadvantages: 1. The detection result of the TC control system will drift. 2. The period of recalibration is longer. 3. The change in temperature and relative humidity inside the box will affect the accuracy of the sensor. When the door is frequently opened, not only the CO 2 concentration, but also the temperature and relative humidity fluctuate greatly, thus affecting the accuracy of the TC sensor. This control system is less suitable when precise culture conditions are required and the incubator door is frequently opened. (2) Infrared (IR) sensor The infrared sensor (IR) system includes an infrared emitter and a receiver detector. When the CO 2 in the tank absorbs part of the infrared light emitted by the emitter, the receiving detector can detect the amount of infrared radiation and is absorbed by the infrared light. The amount corresponds exactly to the level of CO 2 in the tank, so that the concentration of CO 2 in the tank can be obtained. Compared with the TC system, the IR system has higher stability, no drift in detection results, and faster recalibration, so the price will increase. The carbon dioxide incubator currently on the market is conventionally equipped with a TC system. Of course, some manufacturers pay more attention to the precise control of the concentration of CO 2 . All the carbon dioxide incubators in the factory are equipped with an IR system, such as Esco, Singapore. However, not all CO 2 concentration infrared sensors work the same way. There are three main methods based on the principle of non-dispersive infrared gas detection: single beam single wavelength measurement, dual beam dual wavelength measurement and single beam double Wavelength measurement. Single beam single wavelength measurement, as the name implies, this CO 2 sensor can only provide a single wavelength of light, due to its stability vulnerable to aging, such as lamps, dust contamination factors, temperature changes and the light emission characteristics change, and thus which measures The stability and accuracy are not accurate enough. Dual-beam dual-wavelength measurement, this measuring instrument is equipped with 2 lightwave channels, 1 detector and 2 filters. Compared with the single-beam single-wavelength measuring instrument, the accuracy and stability are improved, but in the In practical applications, the degree of influence of the two optical wave channels will also bring the accuracy of the measurement instrument to the accuracy of the misalignment due to the asymmetric influence. Single-beam dual-wavelength measurement ensures high-precision control of carbon dioxide concentration, avoids errors caused by double-beam attenuation interference, and avoids instability of single-beam single-wavelength probe. It best protects valuable culture materials. . Esco's direct thermal carbon dioxide incubator uses a Finnish Vaisala single-beam dual-wavelength IR sensor. The three-gas cell incubator adds an oxygen concentration control system to the carbon dioxide incubator. 4 how to achieve precise temperature control To maintain the vigorous growth of cultured cells, there must be a constant and appropriate temperature. Different types of cells have different culture temperature requirements. For example, the suitable culture temperature of fish, insects and amphibians is 25-28 ° C, the suitable culture temperature of mammalian cells is 35-37 ° C, and the transformed cells are suitable for high. It was grown at 40 °C. The standard temperature for human cell culture is 36.5 ° C ± 0.5 ° C. Deviating from this temperature range, the normal metabolism of cells will be affected or even die. Maintaining a constant temperature in the incubator is an important factor in maintaining healthy cell growth. The temperature of the CO 2 incubator is heated by a heating wire, and there are mainly two heating systems of water jacket heating and gas jacket heating. (1) Water jacket heating Water jacket heating maintains a constant temperature by enclosing an internal tank through a separate water jacket. The advantage is that water is a good thermal insulation material. When a power failure occurs, the water jacket system can Keeping the temperature accuracy and stability in the incubator for a long time is beneficial to users who are not stable in the experimental environment (such as useful power limitation or frequent power outage). (2) Air jacket heating The gas-sleeve heating is to directly heat the inner tank through the heaters in the gas jacket of the tank, and is also called direct heating on six sides. Compared with the water jacket type, the gas-sleeve type has the characteristics of quick heating and rapid recovery of the temperature than the water-type incubator, which is particularly advantageous for short-term cultivation and the need for frequent switching of the box door. In addition, the air-sleeve design is simpler for the user than the water jacket type (the water jacket type needs to add water, empty and clean the water tank, and often monitor the operation of the water tank, as well as potential pollution hazards). The advantages of gas-sleeve heating are summarized as follows: 1. Lighter weight, more convenient for transportation or handling; 2. Faster heating, faster temperature recovery than water-type incubator, especially for short-term cultivation and the need for frequent switching of the box door 3. No contamination of the sample due to water leakage; 4. More sterilization methods can be selected (water jackets use water as a heat transfer medium, and high temperature heating sterilization is difficult). In order to meet the training needs of the low-temperature, carbon dioxide incubator manufacturers make every effort to develop a system of built-in refrigeration products available researchers choose, for example, Esco company CelCulture ® series of carbon dioxide incubator built-in cooling system provides highly specialized solutions for applications, refrigeration system allows sample The study was carried out at high/lower temperature conditions. 5 how to meet the requirements of cell culture humidity Water is an important part of cells. In the process of culturing cells in an incubator, the most direct effect of cooling or heating is that the medium of the cells evaporates quickly and dehydrates. Evaporation will lead to enhanced penetration and permeation on the medium. Sexual dehydration; the salt concentration in the medium increases, the water in the cells runs out of the extracellular cells, the metabolism slows down, and the cells die. The control room of the relative humidity in the incubator is very important. The saturated humidity environment can avoid the escape of carbon dioxide in the culture solution, keep the pH stable, and prevent the evaporation of water in the culture solution due to drying, and the osmotic pressure is increased, resulting in cell culture failure. Most carbon dioxide incubators generate moisture through the evaporation of humidification trays. Large carbon dioxide incubators use steam generators or sprayers to control relative humidity levels. Some incubators have a humidity reservoir at the bottom to enhance evaporation, but the system is also more complex, and some unpredictable problems can arise during use due to the addition of complex structures. 6 How to effectively control pollutants Cells cultured in vitro lack anti-infective ability, so prevention of contamination is the primary condition for determining the success or failure of culture, and thus it is necessary to ensure sterility as much as possible during the operation. Carbon dioxide incubators have always been considered by researchers, and manufacturers have designed a variety of different devices to reduce and prevent contamination, giving users multiple sterilization options. (1) Dry heat sterilization A method of coagulating bacterial protoplasts with dry hot air and destroying the bacterial enzyme system to kill bacteria. For Bacillus thermophilus, dry heat sterilization tends to form spores and cannot be completely sterilized at one time. It is usually necessary to culture at 37 ° C to resterilize the spores and then sterilize them to achieve a thorough sterilization effect. (2) moist heat sterilization The high temperature and high pressure water vapor is used as the medium. Because of the large latent heat of steam and strong penetrating power, it is easy to denature or solidify the protein, eventually leading to the death of microorganisms. Therefore, the sterilization efficiency of the method is higher than that of the dry heat sterilization method. Moreover, the moist heat sterilization temperature is lower than the dry heat, and the damage to the electronic components, especially the sensor, is small, and the service life of the incubator can be prolonged. (3) UV sterilization UV sterilization is carried out by irradiation with an ultraviolet tube. Ultraviolet light with a wavelength of 220-300nm is called “killing life zoneâ€. The ultraviolet sterilizing effect depends on the power of the UV lamp and the irradiation time. In addition, many unstable factors such as the space and area of ​​the illuminated light cause the ultraviolet sterilizing effect to be not very high. ideal. In addition, ultraviolet rays have a harmful effect on the human body. (4) Filter sterilization All gases entering the incubator are filtered through a 0.2 μm inline filter to eliminate gaseous impurities and contaminants. Other companies have ULPA ultra-high efficiency filters that filter the air inside the incubator. For example, the Esco CelSafe ® CO2 incubator is equipped with the ULPA ultra-high efficiency filter from Camfil, Sweden, which can remove 99.999% of particles above 0.3um and provide an ISO 3 cleanliness level in the incubator. Contaminants in the environment and in the air in the sample chamber ensure circulation of the air. (5) copper inner liner antibacterial Copper's antibacterial properties have long been recognized worldwide and widely used. Many professional manufacturers have developed mature copper liner carbon dioxide incubators, such as the Esco CelCulture ® copper liner incubator, which provides additional protection for precious samples. (6) Antibacterial coating antibacterial The main component of the externally used bacteriostatic material contains silver ions, which has long-term bacteriostasis and is not eliminated by surface cleaning. E.g. Patent Isocide TM Esco antimicrobial surface coating technology can effectively inhibit microbial growth at the surface of the case, experiments show that the surface of the casing can be suppressed to 99.9% of the bacteria within 24 hours. 7 How to operate and control the CO2 incubator conveniently and efficiently The micro-processing control system mainly includes high-temperature automatic adjustment and tracking alarm devices, CO 2 alarm devices, password protection settings, automatic calibration systems, etc. Some carbon dioxide incubators equipped with high-efficiency filters are also equipped with filter replacement alarm devices. The parameter setting, fault troubleshooting and grading menus are integrated into the operation; the instrument safety status can be clearly displayed, and the temperature and CO 2 concentration can be easily realized in real time; the special sound and light alarm prompt function promptly reminds the user to find and deal with the problem. Some carbon dioxide incubators are equipped with data logging and output functions to facilitate user monitoring and maintenance of the equipment. For example, Esco's carbon dioxide incubator is equipped with a specific intelligent data and event detector recording device, which intelligently records all operating parameters during the use of the incubator, and can retrieve recorded data through the program software on the LCD display. 16M flash memory guarantees long-term storage of operational data. There is also the Esco Voyager ® software package, which is connected to the Esco CO2 incubator via RS485 using the Esco bus communication protocol for remote monitoring, data logging and programming of the device. Up to 16 devices can be connected to the same computer, and emails that record data are automatically sent at user-set intervals, providing an extra layer of protection for the user's precious samples. 8 How to use the carbon dioxide incubator correctly Esco has previously issued a note entitled "Use of Carbon Dioxide Incubators, do you know?" "A article, interested pro, you can go to our official website to understand, or pay attention to Esco's life sciences WeChat public number: Esco_China, to learn more about the carbon dioxide incubator. covid19 Anesthesia Medical Co., Ltd. , https://www.trustfulmedical.com
