In biochemical experiments, buffer solution plays an indispensable role, it can resist the influence of a small amount of strong acid and strong base, to maintain the pH value closest to the physiological environment for the system. Both HEPES and Tris buffers are commonly used in biological experiments, and many people often wonder: what's the difference? This article will summarize the comparison.
Introduction and application
HEPES (4-hydroxyethyl piperazine ethylsulfonic acid) : an amphoterium ion biological buffer, Belongs to Chromogenic reagent
， with an effective buffer range of 6.8~8.2, which can be widely used in a variety of biochemical reactions and as a buffer in some cell media. The final concentration was 10~50mmol/L, and the buffer capacity was reached when the medium contained 20mmol/L. In addition, because of the absence of cytotoxicity, HEPES buffers are often used in organelles and in the study of extremely volatile, ph-sensitive proteins and enzymes, as well as in biochemical diagnostic kits, DNA/RNA extraction kits, and PCR diagnostic kits.
: Tris is weakly alkaline, pKa is 8.1 at 25°C, the effective buffer range of its buffer is between pH7.0 and 9.2, and the commonly used pH values in biochemical experiments are 6.8, 7.4, 8.0 and 8.8. It is widely used as a solvent for nucleic acid and protein, and for the formation of intermediate fibers in nematodes. Derived buffers such as TE, TAE and TBE are commonly used for DNA stabilization, storage and extraction.
Characteristics of HEPES buffer:
1. PKa value is between 6.0 and 8.0;
2. High solubility in water;
3. It has membrane impermeability and is not easy to penetrate the biofilm;
4. It has limited influence on biochemical reactions, can resist chemical and enzymatic hydrolysis, and does not form complexes or precipitate with metal ions;
5. Extremely low absorption of visible and ultraviolet light;
6. Ion concentration, solution composition and temperature have little effect on dissociation;
Characteristics of Tris buffer
1. It is alkaline in nature, and only the tris-hcl buffer system can be used to prepare buffer with pH range from acidic to alkaline, and it can be combined with other substances to form a variety of buffer systems, such as TE, TBS, TAE, TBE and other derived buffer;
2. Little interference to biochemical process, no precipitation with calcium, magnesium and heavy metal ions;
3. Greatly influenced by the solution concentration, the pH value was more than 0.1 when diluted by 10 times;
4. It is greatly affected by the environment. Generally speaking, pH value decreases by 0.03 for each degree increase in temperature; It absorbs CO2 easily from the air.
In summary, HEPES
and Tris buffers have certain differences in buffer range, application field, and characteristics. In specific experiments, the experimental conditions need to be carefully analyzed to select the most appropriate buffer system. The HEPES and Tris buffer currently produced and developed by desheng technology has sufficient raw materials, fast delivery speed and purity ≥99%, which can be used in low-temperature biochemical research and as raw materials for various diagnostic kits. First-class r&d equipment and professional scientific research teams will provide customers with first-class quality services and guarantees.