Purification of synexin by pH step elution from chromatofocusing media in the absence of ampholytes.

Synexin can be purified to virtual homogeneity by a modification of the conventional chromatofocusing technique. Ampholytes are omitted from the procedure altogether and the protein is eluted by a specific pH step chosen on the basis of the pI of the protein. This modification of the conventional method eliminates the separation of ampholytes from the purified protein, an insurmountable problem in our case, and reduces the cost of purification profoundly.