ABSTRACT
The organism is organized at the cellular level so that enzyme distribution is not uniform. After a decision has been made as to source of enzyme to be used, the next step is to extract the enzyme from the tissue and to proceed with purification. For purification of enzymes, ice baths, cold rooms, and refrigerated centrifuges are a necessity. Electrophoresis is generally used for determination of protein purity rather than for purification. Since enzymes are quite specific, use of various substrates permits a determination of different types of enzymes present in the mixture. Separation of proteins on the basis of molecular size by gel filtration should always be considered among the steps used for purification of a protein. There may be growth conditions that increase the enzyme concentration. In the case of microorganisms and to some extent animals, the amount of enzyme may be increased by varying the composition of the growth medium.
