|
OraChrom, Inc. |
|
|
|
|
|
|
STYROS™
AL,
STYROS™
EP,
STYROS™
OH,
Activated Affinity Simulated Monolith™
columns for High Speed, High Performance Liquid Chromatography.
Product description STYROS™ AL, EP and OH series are a new line of Simulated Monolithä packed columns made of polymeric media intended for the affinity chromatography of proteins, peptides and other biomolecules such as polynucleotides with user-immobilized ligands. The base monolithic matrix that is fully pervious is made of highly crosslinked poly (styrene-divinylbenzene). It is then covalently coated with a layer of hydrophilic ligand in order to preserve the pore structure of the media. The unique macroporous structure of the bed provides a maximum surface contact as well as a uniform flow path, making it possible to run high speed, high-resolution separations without any mass transfer restrictions. Unlike soft gel, Simulated Monolithä columns can be used at high backpressures, reducing considerably the run time. Typical linear flow rates are 1,800 cm/hr or above, compared to 140 cm/hr with soft gel. Unlike Monolith, there are no limitations with Simulated Monolithä columns. They are available in most sizes and configurations. Higher practical and efficient use of the column is another advantage of such products. STYROS™ media are available in many different sizes and performance series. Make sure to select the appropriate one for your application.
Technical Specifications
Chemical and Physical Resistance
Online Activation. Unlike batch activation, online activation with STYROSä Activated Affinity Simulated Monolith™ columns is more controllable and more reproducible. Minute amounts of rare proteins can be immobilized on the proper size column while monitoring the process through a detector. The choice of different functionalities including the OH surface provides the possibilities of a wide range of reactions that the end user has at his disposal to immobilize a protein of interest on the media’s surface. Many factors hold true during the on line immobilization process compared to in batch immobilization, while others become less important. For example, the reaction time is controlled by the flow rate. The notion of concentration changes from overall to local. There is no need for extreme salt concentration in order to salt out the protein to the surface and induce reaction. The immobilization time is reduced from days to hours. The proteins are less likely to become denatured as a result of long shaking and mechanical forces. Once immobilized, the protein becomes more stable if kept under proper conditions. Many immobilization procedures, both on line and in batch have been described in details in the published literature. The end user is to make the proper choice for the specific protein that is to be used.
General Chemistry of Immobilization STYROSä AL The reaction is carried via reductive amination using primary amines form the substrates to be immobilized. The following figure summarizes the reaction.
STYROSä EP The epoxy function with an oxirane ring reacts at low pH’s of 7.5 to 8.5 with thiol groups since they are stronger nucleophiles than amine and hydroxyl groups. The pH required for the hydroxyl reaction is between 11 and 12 and for the amino group it is above 9. It becomes therefore possible to selectively choose to immobilize substrates through their sulfhydryl rather than their amine groups. The epoxy reaction with a primary amine can be summarized as follow:
STYROSä OH As a stable polymeric surface, STYROS™ OH provides all the coupling chemistries that are used for soft gel media that includes: Carbonyldiimidazole Cyanogen bromide Diazaonium Divinylsufone Glutaraldehyde Tresyl Triazine
Considering the added stability of STYROS™ media, it is possible to carry the above reactions safely, without altering the structure of the stationary phase. The protocols for the chemistries mentioned above are well described in classical textbooks.
|
|
Copyright © 1997-2009
OraChrom, Inc.
|
