1.14.13.50 | frozen pellet of cell culture is suspended in lysis buffer (50 mM Tris-HCl, pH 7.7, 025 mM phenylmethanesulfonyl fluoride, 1 microM pepstatin A, lysozyme), cells disrupted by sonication, centrifuged, supernatant purified by affinity chromatography, mixed with Ni-NTA agarose medium, washed, packed into a column, eluted, active fractions combined and stored in buffer (20 mM phosphate buffer, pH 7.0, 0.25 mM phenylmethanesulfonyl fluoride, 5% glycerol) |