CAPSO sodium salt

CAPSO (N-cyclohexyl-2-hydroxyl-3-aminopropanesulfonic acid) sodium salt is used to formulate CAPSO buffer, a zwitterionic buffer that is useful in the range of pH 8.9 - 10.3. CAPSO buffer is used in western and immunoblotting experiments as well as protein sequencing and identification. Used in the electrotransfer of proteins to PVDF or nitrocellulose membranes. The high pH of this buffer makes it useful for the transfer of proteins with a pI > 8.5. CAPSO is not one of the original “Good” buffers, although it has a similar structure to the other propanesulfonic acids and was selected as a highly water soluble buffering reagent with an optimum buffering pH of 10.4 and minimal reactivity with enzymes or proteins, minimal salt effects.