All living systems contain buffer solutions to sustain the structure and activity of biological components such as DNA, RNA, proteins, carbohydrates, and lipids. Buffer solutions are remarkably resistant to pH changes and generally consist of a weak acid and its conjugate base or a weak base and its conjugate acid. In the laboratory, artificially made buffers are often used to help maintain a biological system at the proper pH.
A laboratory buffer should be inert in the system being studied. For example, Tris buffer is unsuitable for some protein assays because it reacts with the assay components. Phosphate buffers contribute phosphate ions to a solution, which inhibit some types of enzyme reactions such as alkaline phosphatase. Tris-Borate-EDTA (TBE) buffer and Tris-Acetate-EDTA (TAE) buffers are most commonly used for DNA gel electrophoresis. However, because the borate reacts with hydroxyl group …show more content…
The equation C1V1 = C2V2 (Concentration_stock × Volume_stock = Concentration_final × Volume_final) is used to determine how much of the concentrated stock solution is needed for making a diluted solution. It is important to plug in the identical units of concentration and volume of both stock and final solutions into the equation in order to get a correct answer. Some buffers change pH when diluted. If the pH change by dilution is not acceptable, then use of stock solution should be avoided. Some buffers, especially Tris, change pH when the temperature changes. So, it is important to adjust the pH at the same temperature as the buffer that will be used. Solubility of buffer should be also taken into consideration; sodium phosphates are quite insoluble at low temperature unlike potassium phosphate. However, potassium phosphate buffer is useless if SDS (sodium dodecyl sulfate) is added to the buffer because potassium reacts with SDS to make an insoluble
A laboratory buffer should be inert in the system being studied. For example, Tris buffer is unsuitable for some protein assays because it reacts with the assay components. Phosphate buffers contribute phosphate ions to a solution, which inhibit some types of enzyme reactions such as alkaline phosphatase. Tris-Borate-EDTA (TBE) buffer and Tris-Acetate-EDTA (TAE) buffers are most commonly used for DNA gel electrophoresis. However, because the borate reacts with hydroxyl group …show more content…
The equation C1V1 = C2V2 (Concentration_stock × Volume_stock = Concentration_final × Volume_final) is used to determine how much of the concentrated stock solution is needed for making a diluted solution. It is important to plug in the identical units of concentration and volume of both stock and final solutions into the equation in order to get a correct answer. Some buffers change pH when diluted. If the pH change by dilution is not acceptable, then use of stock solution should be avoided. Some buffers, especially Tris, change pH when the temperature changes. So, it is important to adjust the pH at the same temperature as the buffer that will be used. Solubility of buffer should be also taken into consideration; sodium phosphates are quite insoluble at low temperature unlike potassium phosphate. However, potassium phosphate buffer is useless if SDS (sodium dodecyl sulfate) is added to the buffer because potassium reacts with SDS to make an insoluble