Amintra Affinity Resins FAQs

1. What is the shelf-life of Amintra Glutathione resin?

The resin is guaranteed for 24 months after the date of manufacture provided they are stored at 2-8˚C.

2. Do I need to filter the buffers prepared in my laboratory?

It is good laboratory practice to filter all buffers using a 0.45 micron filter.

3. How should I prepare my buffer the Amintra Glutathione resin?

Elution buffers, in particular, should be prepared fresh before use. Reduced glutathione gradually becomes oxidized in solution. It is recommended that you add fresh reduced glutathione and/or other reducing agents to the elution buffer just prior to use. You will need need to re-adjust pH of the buffer system after addition of reduced glutathione.

4. How should I prepare my sample the Amintra Glutathione resin?

It is recommended that all samples are filtered to at least 0.45 µm pore size.

5. Should I add b-mercaptoethanol or DTT to the lysis buffer?

Concentrations less than or equal to 10 mM βmercaptoethanol or DTT can be used with this resin.

6. Should I be concerned if the resin partially dried out during the chromatographic steps?

The resin is robust. Partially dried resin rehydrates rapidly. There are no adverse effects upon the performance of the resin.

7. Do I need to remove the GST-tag from the recombinant protein?

Typically a protease cleavage site is engineered between the GST-tag and the target protein. The GST-tag can be cleaved on the column or in solution after elution. Cleavage of the GST tagged protein on the column eliminates the need to separate the protein from the GST tag at a later date as the GSTtag remains bound to the column. When protein precipitation is observed during cleavage Expedeon’s Stabil-PAC (# STP) can be used to maintain protein solubility.

8. What are the endotoxin levels in the resin?

The endotoxin levels are below the detection levels.

9. Do you have any data regarding ligand leakage?

Ligand leakage, at the point of coupling, is negligible.

10. Can I regenerate the resin?

Regenerate the column by passing 5 CVs of 0.1 M Tris/HCl buffer, 0.5 M NaCl, pH 8.5, then 5 CVs of 0.1 M sodium acetate buffer, 0.5 M NaCl, pH 4.5 and finally 5 CVs of either 1X PBS buffer pH 7.2 or running buffer. Alternatively, use 3 CVs of either 6M Guanidine HCl, 70% ethanol or 0.1M NaOH for cleaning followed with at least 5 CVs of either 1X PBS buffer pH 7.2 or running buffer.

11. Can I re-use the resin?

The resin can be re-used. Re-use does depend on the properties of your target protein. You may observe that flow rates slow down in successive bind-washelute cycles as more samples are progressively loaded on to the columns. In addition, if the resin is not regenerated, binding capacity may be reduced.