The tentacle
Long, linear polymer chains, the so called "tentacles," are covalently
attached to hydroxyl groups of the backbone structure of Fractogel®
EMD. These molecular tentacles are forming the unique structural environment
for the binding and desorption of proteins or other compounds.
Appropriate functional ligands are covalently bonded to the tentacles.
Thus, a loss of functional ligands or complete tentacles during chromatography
and regeneration, including sanitizing, cannot occur.
The main advantage of the tentacle chemistry is the large
amount of sterically accessible ligands for the binding of biomolecules
without any steric hindrance. Different ligands are utilized for various
application areas (ion exchange, affinity-, hydrophobic interaction
chromatography). |
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The matrix
The structure of the Fractogel® EMD particles is considerably different from that of other
hydrophilic chromatographic resins like dextran, agarose or cellulose. |
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Fractogel® EMD is a synthetic methacrylate based polymeric
resin providing a excellent pressure stability resulting in high flow
rates. The process media consist of beads with a particle size between
40 and 90µm. Fractogel® EMD BioSEC for size exclusion chromatography
has a particle size in the range of 20-40µm. The pores which
are formed from intertwined polymer agglomerates, have a size of about
800Å enabling a free diffusion of proteins into the beads.
The complete surface is strongly hydrophilic due to the ether linkages
in the polymer.
The cleanability of Fractogel® EMD guarantees a long lifetime. Due to the chemical
resistance of Fractogel® EMD a high number of cycles can be achieved and, thus, the
purification of bio-molecules can be performed very economically.
| Summary: Properties of Fractogel® EMD media: |
| Matrix |
crosslinked polymethacrylate |
| Particle Size |
S-type: 20-40µm, M-type: 4-90µm |
| Pore Size |
About 800 Å |
| pH Stability Range |
pH 1 up to 13 |
| Pressure Limit |
20 bar |
| Linear Flow Rate |
up to 800cm/h, depending onthe column dimensions |
| Storage |
150mM NaCl, 20% ethanol |
| Sanitization |
0.1-1.0M NaOH |
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