Fractionating the Carrier Ampholytes

Sometimes it is desirable to cover a pH-gradient smaller than 3 to 10. In this case fractionation is necessary in order to obtain the suitable mixture of carrier ampholytes for the purpose. This may be carried out satisfactorily in a multichamber according to principles similar to those described by Williams and Waterman (12). 

The apparatus described by Vesterberg (26) had 20 chambers separated by sieve membranes of polyvinylchloride paper. Cooling water was circulated through narrow glass tubes in each cell. The original mixture from the synthesis of carrier ampholytes was poured into the cells. Current was applied via the platinum electrodes in the two end chambers. After about 24 hr the ampholytes had separated, the most acidic ones 

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