Electrophoresis in polyacrylamide gel (12 %) of sonicate containing A-alpha (Fig. 1.)
Fig. 1. Sonicate containing A-alpha protein fusion
The arrow shows place of our overexpressed protein:
1. Marker
2. sonicate A-alpha with induction
Michał L.
Supernatant containing A-alpha was mixed with NiNta bead in proportion 10:1 and placed on rotating platform for 30 min at 4°C
Bead was spun down at 6000 RPM, 5 min at 4°C
Supernatant was discarded and equal amount of Elution buffer 1 (Sonication buffer A suplemented with 50 mM imidazole) was placed on top of the bead
Bead was spun down at 6000 RPM, 5 min at 4°C
Supernatant was collected for further analysis and equal amount of Elution buffer 2 (Sonication buffer A supplemented with 100 mM imidazole) was placed on top of the bead
The above two steps were repeated for elution buffers 3 and 4 (150 mM and 200 mM imidazole)
All fractions obtained in this procedure were resolved on 8% SDS-PAGE gel. It turned out that optimum imidazole concentration for elution of His-tagged A protein is 150 mM