Protein Purification and Method Development Using PhyTip Columns
Protein Purification and Method Development Using PhyTip Columns

PhyTip Column Resins Q&A

How do I know if I am using the right antibody affinity resin? For example, I am using a mammalian expression system and isolating mouse IgG3? What resin should I use?

PhyNexus’ support is available to help choose the correct resin for a particular application. When in doubt, call us! In the example posed in the question, ProA may not be the optimal resin for isolating mouse IgG3. We recommend using ProPlus or ProPlus LX resin which has a stronger affinity for this particular protein over ProA resin. In addition, Mammalian expression systems frequently do not produce very large quantities of the desired protein, so choosing a resin with a higher affinity may allow you to capture more of the product.

How long can refrigerated Affinity PhyTip columns be stored?

Each PhyTip column is manufactured and shipped with a special bead coating liquid to maintain bead hydration and prevent contamination. The tips are guaranteed to remain stable for at least six months after delivery. They will remain stable, hydrated and usable for many more months.

If I let the Protein A PhyTip column dry out while I’m using it, will the captured protein be affected?

For optimal recovery and to avoid protein denaturing, PhyTip columns should remain hydrated through the entire purification process. But there is little danger. The columns are shipped with a coating liquid to prevent the resin bed from drying. Depending on the resin, and in some cases, column styles, the bed may be translucent, partially opaque or completely opaque. The columns may be stored at room temperature in robotic systems for hours or even days (even weeks) with no danger of column damage. Once the purification process has been initiated, the columns will not dry out if used under recommended operating conditions.

What is the IMAC resin made of and why does my IMAC resin have a blue color?

A PhyTip column with IMAC resin is made of Ni-NTA (chelating) functional group bonded to an agarose resin substrate. The nickel cation, held by the NTA (nitrilotriacetate) chelating group, has an affinity for 6-HIS tag portion of a recombinant protein. Generally, there are two basic IMAC resins available: a nickel based and a cobalt based system. Cobalt resins have a slight pink/red tinge to the resin. The Nickel resin with a bluish color tinge and is the most common type of IMAC resin.