{*Figure 13*}Protein/Enzyme Purification -- Part II
HOME PAGE
Determination of Purity of Enzyme after Purification Procedure
Although several methods are available for determining purity,
the easiest to apply and best method is PolyAcrylamide Gel Electrophoresis (PAGE).
Thus, determination of purity is done by PAGE:
{*Figure 13*}
Illustration of the setup of a PAGE apparatus and concept of using electric charge to drive protein separation.
In electrophoresis, the proteins are applied to the gel and...
separated by applying a high voltage across the gel for ~1 hour.
Proteins migrate in an electric field because they are charge at the pH of buffer used in PAGE.
After the separation is completed, the gel is stained with a dye to reveal the positions of the proteins in the gel.
[Figure 13 is from Voet & Voet Biochemistry Text ©1990 John Wiley & Sons]
Native Molecular Weight and Subunit Composition. -- Section B
Native MW is estimated by gel filtration and... -- Section C
Determining the Number of Subunits by SDS-PAGE -- Section D
©Wilbur H. Campbell, 1995; wcampbel@mtu.edu