Activity gel assays require a long incubation time (several hours) on renaturation of enzymatic activity after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). To reduce the incubation time, we used a novel renaturation buffer containing cyclic oligosaccharide beta-cyclodextrin (beta-CD) which is capable of capturing SDS. Yeast alpha-glucosidase, used as a model protein, was run on SDS-PAGE, and then the gel matrix was incubated in a variety of renaturation buffers. Compared with conventional renaturation buffers containing Triton X-100 or isopropanol, our novel renaturation buffer containing beta-CD can restore enzymatic activity within 10 min. Therefore, this new format represents a good alternative with reduced incubation time for activity gel assays.