The resin-bound protein was eluted step by step by gravity flow with increasing concentrations of imidazole (10 mM, 100 mM, and 200 mM in buffer containing 200 mM NaCl and 20 mM Tris HCl, pH 7.4).
If the crystals were originally precipitated in shallower environments and secondarily transported to the deeper slope/basin by gravity flow, the long axis of each crystal should be aligned parallel to the bedding, which clearly differs from the observed randomly oriented texture of the Chaotian crystals.
After removal of the unbound material by gravity flow, the Ni-NTA beads were washed twice with total of 40 ml of Wash buffer B (100 mM NaH2PO4, 10 mM Tris, pH 8.0, 8 M urea, 5 mM imidazole, and 1 mM PMSF), and eluted 4 times with 1 ml of Elution buffer C (100 mM NaH2PO4, 10 mM Tris, pH 8.0, 8 M urea, 20 mM EDTA, and 400 mM imidazole).
The sewage reaches the North River plant by gravity flow — running downhill to the plant from the higher elevations of Washington Heights and Inwood, and down an artificial slope from Lower Manhattan.
The expressed protein was applied into the column by gravity flow.
The bound proteins were eluted from the beads by gravity flow in a Bio-Rad mini-column with increasing concentrations of imidazole (Sigma) in Ni-NTA wash buffer.
The DNA solution was loaded onto the QIAGEN-tip and allowed to enter the resin by gravity flow.
Apply the DNA sample from Step 76 to the QIAGEN column and allow it to enter the resin by gravity flow.
The source area capable of supplying sediment to the basin by sediment gravity flow (white dotted line in Figure 1) has an area of about 85 km2.
Wash the column twice with 30 ml of Buffer QC and allow it run through the column by gravity flow.
