General Information
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• pH: PolyAspartamide ion exchange columns are silica based, and as such should not exceed ~pH7. Moderately higher pH will not damage the ligands but will degrade the silica backing. If higher pH is required, be sure to rinse thoroughly with water.
• Organic Solvents: Aspartamide columns will tolerate high levels of organic solvents as well as salt.
• Temperature: Temperatures over 45C will shorten column lifetimes.
• Buffers: Most buffers may be used with Aspartamide columns.
• Filters: Always filter with a 0.20um or finer solvent filter.

Conditioning
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• Flush new columns with 15 CV (column volumes) of water (to remove MeOH used in shipping).
• Condition with 15 CV at 1/2 flow rate of 0.2 NaH₂PO₄ + 0.3 M sodium acetate. The conditioning step will expose all of the ligands for interaction with the mobile phase. Failure to perform this step will result in low or no binding.
• Flush again with 15 CV of water to remove excess salt. Salt is an effective eluting strategy-- its presence on the column prior to binding will affect results.
• Optional for small and/or expensive samples: Inject and rinse through a small quantity of protein such as BSA to fill non-specific binding sites that may be present due to column hardware. Sintered metal frits are known to bind small quantities of proteins that will not be eluted under normal chromatographic conditions.
• Passivating FRITS is recommended for restoring retention times for certain sensitive proteins. All metal frits have the potential for interaction with proteins. If you experience variable retention times of some of your proteins, but not necessarily all of them, after a period of use, then you may need to passivate the frits. Flush the column with water, then with 50 mM di-sodium EDTA over night at a reduced flow rate.  The pH should be between 3.0 and 7.0.

Storage
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• Use proper storage conditions, even if for overnight.
• Flush the column with 10 CV of water or weak acid buffer such as 1mM EDTA.
• Store wet.
• Keep columns cool(ca. 4C). Long term storage is best when refrigerated (not frozen).
• Condition prior to re use w/ 10CV high salt buffer.

In the refrigerator, microbial growth is minimal even if stored in 100% water. Based on our experience, it is possible to store it in ACN/water=50/50, or perhaps 75/25, without having to perform conditioning again. If you're going to use the column within a day or two, then there's no need to bother with anything but water.

Generally, a column will fail from something other than microbial growth, especially considering that mobile phase conditions with SCX (ion exchange) usually aren't conducive to microbial growth (i.e., some ACN and pH @ 3.0). However, if running ammonium acetate gradients at pH 5.5 without organic, then one has an excellent growth medium for microbes so we recommend flushing with water prior to storage.

If you flush the column with 100% ACN (or any other organic solvent) for storage, then condition the column with high salt when you take it out of storage, as if it were new.

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Cleaning
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• Cleaning requires a gradient of high salt buffer (ca. 1M - 1.5M but depends on solubility with the amount of organic in mobile phase.
• Organic solvents may be used in cleaning methods to maintain solubility of proteins.
• Column may be reversed to reduce traveling distance of contaminants and clear particulates from the frit. Clogged fits may be replaced.

Severe cleaning: 50mM Formic Acid in 40% ethanol:60% water at 1/2 flow rate for 15-20 CV. Follow by repeating the conditioning steps. This step will also remove pyrogens from cation exchange columns.