RESUMO
This work presents a rapid and simple freeze centrifugation method to concentrate dilute protein solutions for detection by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) Coomassie blue staining. Moreover, a simple way to assemble a cryoconcentration device is presented, and its use is discussed. Commercial purified protein standard and an enzyme with high fructosyltransferase (FTase) activity, coming from target fractions obtained by chromatographic separation, were used as an example. FTase, coming directly from the chromatographic fractions, was difficult to view through SDS-PAGE analysis; however, it was easily visualized, and its activity was enhanced, after the application of the freeze centrifugation protocol presented here.
