COMPARISON OF CELL DISRUPTION METHODS FOR DETERMINING BETA-GALACTOSIDASE ACTIVITY EXPRESSED IN ANIMAL-CELLS

To determine beta-galactosidase activity expressed in animal cells, the cells are often disrupted. In this study, four different cell disruption methods (freezing and thawing, sonication, homogenization, and lysis buffer) were compared with regard to their efficiency in the determination of beta-galactosidase activity. Further, the cell lines' susceptibility to cell disruption methods was investigated by employing three different animal cell lines (HeLa HH, Vero, and HeLa S3 cells) infected by recombinant vaccinia virus (vSC8) expressing beta-galactosidase gene. Regardless of cell lines used, three different cell disruption methods except homogenization did not show any significant difference in the final beta-galactosidase activity recovered from the cells. Homogenization was inefficient, and required up to 300 strokes to recover beta-galactosidase activity fully from HeLa S3 cells. The use of lysis buffer was recommendable because of its convenience. However, if there was no need for an immediate assay, it was convenient to keep cell samples collected during the culture frozen at -20-degrees-C until the assay. Since thawing of the cells was enough to recover the beta-galactosidase, further treatment on the frozen cells after thawing was unnecessary.