CAPS

CAPS (N-cyclohexyl-3-aminopropanesulfonic acid) buffer salt is used to formulate CAPS buffer, a zwitterionic buffer that is useful in the range of pH 7.9-11.1. CAPS buffer is widely 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. CAPS is not one of the original Good's 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.