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 (sc-3723) or nitrocellulose membranes (sc-3718, sc-3724). 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 Goods 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.
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