商品名称:碳酸氢钠溶液
Product Description
One of the products of cellular metabolism (i.e., CO2), and the CO2 present in the incubator interact with the water in the medium (Equation #1). Therefore, the H+ concentration is proportional to the CO2 concentration in the atmosphere. The NaHCO3 in the bicarbonate-buffered medium dissociates as indicated in Equation #2. These reactions are in a reversible equilibrium, and the system in toto will have a tendency to resist any change in the ratio between the component parts. When the atmospheric concentration of CO2 is increased, an increase in CO2 and acidity (H+) is prevented by a high HCO3- level achieved by the presence of NaHCO3 (Equation #2). Interestingly enough is another advantage in using the Sodium Bicarbonate is that the absence of either HCO3- or CO2 appears to be limiting in cell growth.
Culture media are often buffered to compensate for the cellular production of CO2 and lactic acid as the by-products of metabolism. Traditionally, basal cell culture media have been buffered by HCO3- (bicarbonate). As cells grow, CO2 evolves, the dissolved CO2 forms a buffering system with the bicarbonate ions. However, if cell density is low or the cell growth is still in the so-called "lag phase," they may not produce sufficient CO2 to maintain an optimal pH. To counter these potential problems, bicarbonate-buffered media require the use of an incubator with a 5 - 10% CO2 atmosphere. Media with low levels of bicarbonate (1.5 - 2.2 g/L of HCO3-), such as MEM, require ~5% CO2, and DMEM with a higher level of bicarbonate (3.7 g/L) requires 10% CO2 in order to maintain the correct pH level. The most important factor in utilizing the correct percent CO2 is based upon the medium's bicarbonate level to maintain the physiological pH, which is irrespective of cell type.
In the human body, the buffer systems are the major mechanism for controlling blood pH which guard against sudden changes in body acidity and alkalinity. pH, as a measure of hydrogen ion activity, is intimately interrelated with the bicarbonate and carbon dioxide concentrations. The pH buffer systems work to minimize changes in the pH of a solution by re-adjusting the proportion of acid to base. The most important blood buffer involves carbonic acid and bicarbonate ions. pH is vital in maintaining homeostasis, and when the environmental pH is beyond the optimal range, proteins may not only be denatured but also enzymes may lose their function thereby causing untoward physiological manifestations (e.g., acidosis/alkalosis). The catalytic activity of enzymes is acutely sensitive in that they have an optimum pH and that their activity declines sharply on either side of the optimum. This is precisely why the biological control of the pH in cells is of central importance in all aspects of intermediary metabolism and cellular functions.
Some Predominant Characteristics of Sodium Bicarbonate Solution (7.5%)
Storage & Stability
This product should be stored at room temperature (15-30°C) and used within the time frame specified on the label. Do not use after the expiration date. Deterioration of the liquid may be recognized by any of the following characteristics, among others including (a) color change, (b) granulation/ clumping, (c) insolubility, and/or (d) decrease in expected performance parameters. The solution with any material described above should not be used and therefore discarded.
Instructions/Procedure
Shanghai Dr. Cell Co., Ltd.
Effective Date
April 2023
Precaution and Disclaimer
For research use only, not for clinical diagnosis and treatment.