1. What type of detergent should I use? Top
In general, non-ionic detergents are better suited for breaking lipid-lipid and lipid-protein interactions. Ionic detergents are better suited for breaking protein-protein interaction. Zwitterionic detergents are useful for breaking protein-protein interaction and they do not bind to ion-exchange resins.

2. How much detergent should I use? Top
Determine the CMC value of the detergent. This information can be found in Calbiochem's catalogs and in the "Guide to the Properties and Uses of Detergents in Biology and Biochemistry." This booklet is available from Calbiochem. One should select a detergent concentration at or slightly above its CMC value.

3. How do I remove detergents from my solution? Top
The method of detergent removal depends upon the chemical properties of the detergent. Detergents with high CMC values can be easily removed by dialysis. Other suitable methods are gel chromatography and ion-exchange chromatography. You can also use our CALBIOSORB™ to quickly remove detergents from your aqueous medium. CALBIOSORB™ is a hydrophobic resin that is processed to eliminate unbound organic contaminants, salts and heavy metals.

4. What type of buffer should I select for my experiment? Top
Select a buffer that has a pKa value close to the middle of the range required. If you expect the pH to drop during the experiment, choose a buffer with a pKa slightly lower than the working pH. This will permit the buffering action to become more resistant to changes in hydrogen ion concentration as hydrogen ions are liberated. Conversely, if you expect the pH to rise during the experiment, choose a buffer with a pKa slightly higher than the working pH. Citrate and phosphate buffers are not suitable for systems that are highly calcium-dependent. Citric acid and its salts are chelators of calcium and calcium phosphates are insoluble and will precipitate out. Use of these buffers may lower the calcium levels required for optimum reaction. Tris (hydroxymethyl aminomethane) is known to weakly chelate calcium and other essential metals.