Description
Guidelines for PolyCAT A capillaries
Structure of Product Description:
Capillary Name- Particle diameter(um)- Pore Size( A)Capillary length(mm)x Capillary ID(mm)
Uniqueness of PolyCAT A Capillaries
PolyCAT A™ is made by attaching covalently poly(aspartic acid) to silica. Proteins elute from this polypeptide coating in sharp peaks with little tailing. Moreover, recovery and binding capacity is high.
Overview of Applications of PolyCAT A column for Cation-Exchange
1) Protein variants involving deamidation, PEGylation, determining position of attachment, desialylation and many more. It is widely used by the biotechnology industry.
2) Hemoglobin variant analysis by clinical chemistry labs.
3) Specifically for Proteins with pI above 6.0 (5.0 in special cases).
4) Monoclonal antibodies.
5) Histones.
Properties of PolyCAT A capillaries for Cation-Exchange
PolyCAT A™ is a weak cation-exchange (WCX) material. It is used at pH values above 4. A gradient to unbuffered acetic acid will uncharged PolyCAT A™, permitting the elution of proteins in a volatile solvent. See our poster on this subject.
Peptides can be run on PolyCAT A™ if they contain at least two excess positive charges above pH 4. More weakly basic peptides, such as tryptic fragments, are not reliably retained. Instead use PolySULFOETHYL A™ at pH = 2.7 – 3.0
For proteins larger than 20 KDa, we recommend the use of pore diameters particles. Use at least 1000 Å Porediameter for optimal selectivity and efficiency. Our 3-µm material with 1000- or 1500-Å pores is the finest cation-exchanger available for protein separations.
How professionals work with PolyCAT A column for Cation-Exchange
Initial Use:
PolyCAT A™ is a silica-based material with a bonded coating of polyaspartic acid. It is a weak cation-exchange (WCX) material. Columns are shipped in methanol. Flush new columns with at least 15 column volumes of water (30 ml for a 200 x 4.6-mm), then condition with a salt solution prior to initial use. A good conditioning solution is 40 mM EDTA.2Na (filtered, but pH not adjusted) at a low flow rate for 20-24 hours.
New HPLC columns sometimes absorb small quantities of proteins or phosphorylated peptides in a nonspecific manner. The sintered metal frits have been implicated in this. Eluting the column for 20-24 hr. at a low flow rate with 40mM EDTA.2Na usually solves the problem. This passivates all metal surfaces in the HPLC system, as well as the column [CAUTION: This treatment can affect the integrity of the frits in some cases, and should probably be avoided with columns packed with 3-µm material. In some cases this has also caused the collapse of 5-µm, 200-Å column packings]. Alternatively, after flushing with water, condition the column for 2 hours with 0.2 M NaH2PO4 + 0.3 M sodium acetate. This solution conditions the coating but does not passivate metal surfaces.
