2011-05-18 (Wed) 02:49:16 Shodex Technical question

Record: 261

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Category: Column Problem Product: KW404 Sample: oligo protein

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Question I’m separating oligo-protein complexes (in PBS or TBS) and am getting low recovery. Is it possible that the oligo is adsorbing to the column? The buffer contains 150mM NaCl. Would there be any benefit to increasing NaCl to 300mM?     Answer There are some cases that certain protein is adsorbed to the gale material of KW400 4F series columns. In these cases, there are various cases. That is, Hydrophobic interaction, ionic interaction, or salting out, for example. If the proteins are typical protein, we think the eluent condition including 300mM of NaCl may improve the recovery of them. The ionic interaction between the surface of the gel material of the ionic group of proteins is the main reason. However, if the proteins are adsorbed to the gel material by hydrophobic interaction, 300mM of NaCl will not work. Is the target protein hydrophobic, or dissolved with any organic solution easily? If so, it may be needed to add some organic solution into the eluent. KW400 4F series columns are usable 100% of methanol or acetonitrile. So, the eluent condition including 20% or more methanol or acetonitrile may be able to improve the recovery. In this case, please note not to make a precipitation of buffer. If the precipitation is made, please try to dilute the concentration of the buffer.     Additional Comments