Ni-NTA Agarose
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- Application
- Purification (Purif), Separation (Sep)
- Purpose
- Specific binding and purification of his-tagged proteins
- Brand
- HighSpec
- Specificity
- Affinity to His-tagged proteins
- Characteristics
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- High binding capacity >70 mg/mL
- Stable in buffer containing 10 mM DTT and 1 mM EDTA
- Delivered as a 50 % suspension
- Average agarose bead size: 40 μm
- Components
- Affinity Agarose
- Material not included
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- Lysis Buffer
- Wash Buffer
- Elution Buffer
- Ice bath
- Refrigerated centrifuge for 50 mL tube (min 10,000 x g)
- 50 mL centrifuge tube
- Micropipettor and Micropipetting tips
- Disposable gravity flow columns with capped bottom outlet, 2 ml
- pH meter
- End-over-end shaker
- SDS-PAGE buffers, reagents and equipment
Optional: Western Blot reagents and equipment
- Bead Ligand
- Ni-NTA
- Bead Size
- 40 µm
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- Application Notes
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For use with: E.coli and eukaryotic cell lysates, cell culture supernatants
Assay Time Procedure: 4-5 h - Comment
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KD of NTA to 6xHis-tag: ca 10 μM
Sample Volume for an assay: >200 mL E.coli culture volume or corresponding quantity. Protocol can be scaled up easily. - Protocol
- Purification of his-tagged protein in batch gravity flow or on FPLC columns
- Reagent Preparation
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A Purification under native conditions:
- Native Lysis buffer: NaH2PO4 50 mM, NaCl 300 mM, Imidazole 10 mM, pH 8
Optional: Add 1 tablet protease inhibitor cocktail to the Lysis Buffer.
Tip: Lysis Buffer contains 10 mM imidazole to prevent binding of untagged proteins. If His-tagged proteins do not bind under these conditions, reduce the imidazole concentration to 1-5 mM. - Native Wash buffer: NaH2PO4 50 mM, NaCl 300 mM, Imidazole 20 mM, pH 8
- Native Elution buffer: NaH2PO4 50 mM, NaCl 300 mM, Imidazole 250- 500 mM, pH 8
Additional chemicals required: Lysozyme, Benzonase® nuclease,
Optional: Protease inhibitor cocktail
B Purification under denaturing conditions:- Denaturing Lysis buffer: NaH2PO4 100 mM, Tris base 10 mM, Urea 8 M, pH 8.0,
Optional: Benzonase® nuclease (e.g. Merck Milipore, #707464) - Denaturing Wash buffer: NaH2PO4 100 mM, Tris base 10 mM, Urea 8 M, pH 6.3NaH2PO4 100 mM
- Denaturing Elution buffer: NaH2PO4 100 mM, Tris base 10 mM, Urea 8 M, pH 4.5
Tip: If the target protein is acid-labile, elution can be performed with 250-500 mM imidazole.
Note: Due to urea dissociation, adjust the pH immediately before use.
- Native Lysis buffer: NaH2PO4 50 mM, NaCl 300 mM, Imidazole 10 mM, pH 8
- Assay Procedure
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A. Protocol for purification under native conditions:
- Thaw the E. coli cell pellets corresponding to 200 mL bacterial culture on ice for 15 min. Optional: Freezing the cell pellet at -20 °C for 30 min prior to incubation at room temperature improves lysis by lysozyme.
- Resuspend the cell pellet in 10 mL Native Lysis Buffer supplemented with 1 mg/mL lysozyme, and pour it into a 50 mL conical centrifuge tube.
- If the solution is very viscous, add 3 units Benzonase® per mL E.coli culture volume to the lysis buffer. Alternatively or additionally, sonicate the lysate to improve cell disruption.
- Incubate on an end-over-end shaker at room temperature for 30 min, or at 4 °C for 1 h, depending on the temperature stability of the protein.
- Centrifuge the lysate for 30 min at 10,000 x g and 2-8 °C. Carefully collect the supernatant without touching the pellet. Note: The supernatant contains the cleared lysate fraction. We recommend to take aliquots of all fractions for SDS-PAGE analysis.
- Resuspend the HighSpec Ni-NTA Agarose by inverting the bottle until the suspension is homogeneous. Transfer 1 mL of the 50 % suspension (corresponding to 500 μL bed volume) to a 15 mL conical centrifuge tube. Allow the resin to settle by gravity and remove the supernatant. Tip: Alternatively, resin equilibration can be performed directly in the disposable gravity flow column.
- Add 2.5 mL Native Lysis Buffer and gently resuspend the slurry to equilibrate the resin. Allow the resin to settle by gravity and remove 2 mL supernatant.
- Add 10 mL cleared lysate to the equilibrated HighSpec Ni-NTA Agarose resin and incubate at 4 °C for 1 h on an end-over-end shaker. Tip: Alternatively, batch binding can be performed directly in a gravity flow column with closed bottom and top outlets.
- Transfer the binding suspension to a disposable gravity flow column with a capped bottom outlet. Use Lysis Buffer to rinse the centrifuge tube and remove resin adhered to the wall.
- Remove the bottom cap of the column and collect the flow-through.
- Wash the column with 5 mL Native Wash Buffer. Repeat the washing step at least 3 times.
- Elute the His-tagged protein 5 times using 0.5 mL Native Elution Buffer. Collect each eluate in a separate tube and determine the protein concentration of each fraction. Optional: Incubate the resin for 15 min in Elution Buffer before collecting the eluate to increase protein yields.
- Analyze all fractions by SDS-PAGE. Note: Do not boil membrane proteins. Instead, incubate samples at 46 °C for 30 min in preparation for SDS-PAGE analysis.
- Optional: Perform Western Blot experiment using PentaHis Antibody.
B. Protocol for purification under denaturing conditions:- Thaw the E. coli cell pellet on ice.
- Resuspend the cell pellet in 10 mL Denaturing Lysis Buffer. Optional: Benzonase® can be added to the lysate to reduce viscosity caused by nucleic acids (3 U/mL bacterial culture). Nucleic acids can also be sheared by passing the lysate 10 times through a fine-gauge needle.
- Incubate at room temperature for 30 min on an end-over-end shaker.
- Centrifuge the lysate for 30 min at room temperature and 10,000 x g. Collect the supernatant. Note: The supernatant contains the cleared lysate fraction. We recommend to take aliquots of all fractions for SDS-PAGE analysis.
- Resuspend the HighSpec Ni-NTA Agarose by inverting the bottle until the suspension is homogeneous. Transfer 1 mL of the 50% suspension (corresponding to 0.5 mL bed volume) into a 15 mL conical centrifuge tube. Allow the resin to settle by gravity and remove the supernatant.
- Add the cleared lysate to the resin and incubate the mixture for 1 h at room temperature on an end-over-end shaker. Tip: Alternatively, batch binding can be done directly in a gravity flow column with closed top and bottom outlet.
- Transfer the binding suspension to a disposable gravity flow column with a capped bottom outlet. Use Lysis Buffer to rinse the centrifuge tube and remove resin adhered to the wall.
- Remove the bottom cap of the column and collect the flow-through.
- Wash the column with 5 mL Denaturing Wash Buffer. Repeat the washing step at least 3 times.
- Elute the His-tagged protein 5 times using 0.5 mL Denaturing Elution Buffer. Collect each eluate in a separate tube and determine the protein concentration of each fraction. Tip: If the target protein is acid-labile, elution can be performed with 250-500 mM imidazole.
- Analyze all fractions by SDS-PAGE. Note: Do not boil membrane proteins. Instead, incubate samples at 46˚C for 30 min in preparation for SDS-PAGE analysis.
- Optional: Perform Western Blot experiment using PentaHis Antibody.
- Calculation of Results
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Analyze by SDS-PAGE, Bradford Assay or spectrophotometrically.
- Assay Precision
- 4.5 h
- Restrictions
- For Research Use only
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- Format
- Liquid
- Storage
- 4 °C
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