用法 :
Procedure for Affinity Purification Using Gravity-flow Column (2 mL)
Note: Adjust volumes of sample and buffers accordingly.
Additional Materials Required:
• Binding/Wash Buffer: 0.1M sodium phosphate, 0.15M NaCl, pH 7.2
• Elution Buffer: 6M guanidine•HCl
• Storage Buffer: 0.05% sodium azide
A. Affinity Purification
Note: Perform chromatography at 4°C.
1. Resuspend product and dispense appropriate volume into Gravity-flow Column. Instructions below are for a 2 mL column.
2. Remove top cap and twist off bottom tab from column. Place column in a test tube and allow storage solution to drain.
3. Equilibrate column with 10mL of Binding/Wash Buffer. Do not allow resin to run dry; always recap column or proceed to the next step as soon as solution drains down to top of resin bed.
4. Mix equal volumes of antiserum and Binding/Wash Buffer. For optimal results, mix 3mL antiserum with 3mL Binding/Wash Buffer.
5. Apply buffered sample to the column.
6. Collect 0.5-1.0mL fractions. Monitor fractions by measuring the absorbance at 280nm relative to a buffer blank. All fractions above baseline contain protein without antibodies against GST.
7. Wash the column with 10mL of Binding/Wash Buffer, continuing to collect fractions.
8. Pool fractions that contain protein.
B. Elution of Bound Anti-GST Antibody
1. Apply 10mL of 6M guanidine•HCl to the column. Collect 0.5-1.0 fractions. These fractions will contain undesired antibodies that recognize the fusion protein′s GST portion.
2. Measure the absorbance of fractions at 280nm to verify the presence of the undesired anti-GST.
C. Column Regeneration and Storage
Note: To regenerate column, the anti-GST antibody must be eluted as described in Section B.
1. Apply 10mL of water, followed by 10mL of the Binding/Wash Buffer.
2. For storage, wash the column with 10mL of 0.05% sodium azide in water or buffer.
3. Cap column when approximately 1mL of solution remains above the top porous disc.
4. Store column upright at 4°C. Immobilized GST can be regenerated and reused a minimum of nine times.
Additional Information/Tips:
• Remove air bubbles from columns to restore flow rate.
• Degas buffers for use in affinity and gel filtration columns.