Cyclohexylpropanesulfonic acid CAPS, CAS No. 1135-40-6, is an important chemical raw material. It is usually used as a biological buffer in biochemical experiments to maintain the pH of the reaction system. There are many types of biological buffers, so which experiments can CAPS be used for? This requires first understanding how to choose a buffer.
1.Selection of buffer pH range:
The buffering range of the buffering agent must first conform to the pH value of the reaction system, such as the reaction condition pH value, protein activity, or enzyme catalyst pH value. The buffer range of the buffer depends on its ionization equilibrium Changshu pKa value. The pH value of the buffer solution is related to the ionization equilibrium constant of the acid and the concentration of salt and acid. The formula for calculating the pH value of the solution is: pH=pKa-lg(Na/Nb ), Na and Nb respectively represent the amount of conjugated acid and alkaline substance. The buffer range of the buffer is between the plus and minus 1 of the negative logarithm of its power balance constant, and pH=pKa±1. The pKa of CAPS is equal to 10.4, the theoretical buffer range is 9.4-11.4, in order to ensure accuracy in biochemical experiments The upper and lower limits are reduced by 0.3 to use 9.7-11.7, so the pH of the experimental system that can use CAPS as a buffer must be in this weakly alkaline pH range.
Common buffer buffer range
2. the ionization balance of commonly used buffers Changshu and buffer range
In many reactions such as complexometric titration, spectrophotometry, and enzymatic reaction, the pH of the solution is required to be kept within a range to ensure the color change of the indicator, the color development of the color reagent, and the optimal pH value for enzyme catalysis, etc. These conditions are achieved by adding a certain amount of buffer solution, so the buffer solution is a reagent often required in analytical tests. Using the potentiometric titration method to determine the titration curve of added acid or alkali to the same buffer solution with different ratios, not only helps to understand the concept of buffer solution and buffer capacity (range) but also to correctly select the preparation method and dosage of buffer solution in analytical testing Instructive. It can be seen from the chart that CAPS is higher among buffers and belongs to weak alkaline buffer.
3. Restrictions on the use of buffers
In the case where the buffer range meets the reaction system, it is also necessary to consider the limiting conditions of the reaction system, for example, phosphate buffer will complex metal ions calcium, enzymes, etc., and the activities of enzymes and proteins in some reactions are affected by metal ions. Phosphate buffer cannot be used. CAPS buffer is suitable for the electrophoresis buffer of high molecular weight proteins (greater than 20KD); if it is a low molecular weight protein blotting experiment, Tris + glycine is usually used, and Tris-Tricine + EDTA is used to exclude glycine for protein sequencing.
In addition to being used as a biological buffer, CAPS reagents are also commonly used in waterborne coatings and other industries. Desheng has extensive experience in the production and development of cyclohexylamine propanesulfonic acid and other various biological buffers, which is worthy of the majority Customer trusted partner!
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