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Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 DEF

Substituted cellulose derivative that is used in bead form as weak ion exchanger. The most frequently used products are DEAE-cellulose (diethylaminoethyl) and CM-cellulose (carboxymethyl), which are weak base (anion) and weak acid (cation) exchangers, respectively. They are prepared from cellulose by substitution of some primary and secondary hydroxyl groups of the anhydroglucose units with diethylaminoethyl or carboxymethyl groups, respectively, joined through ether linkages.  1, record 1, English, - cellulose%20ion%20exchanger

Record number: 1, Textual support number: 1 CONT

Ion exchange celluloses can be used in both column and batch processes, although for large-scale work difficulty has been encountered in using large columns of these materials. The cellulose is easily compressed, and this leads rapidly to a reduction in flow rate. Thus the main application of ion exchange cellulose in large-scale enzyme purification has been for batch adsorption and batch elution.  3, record 1, English, - cellulose%20ion%20exchanger

Record number: 1, Textual support number: 1 OBS

These exchangers have an open structure, which is readily penetrated by large molecules, and a large surface area giving them a high capacity for absorption of protein. The binding is usually freely reversible. DEAE-cellulose is used for chromatography of acidic and slightly basic proteins at pH values above their isoelectric point. The most useful range is pH 6-8. CM-cellulose is used for separation of neutral and basic proteins, which bind at around pH 4.5. Desorption of proteins from the ion exchangers is accomplished by changing the pH or increasing the ionic strength of the eluant.  1, record 1, English, - cellulose%20ion%20exchanger

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 CONT

L'industrie biologique utilise aujourd'hui les techniques chromatographiques pour la production de protéines purifiées. L'insuline par exemple, est isolée à partir de pancréas de bovins ou de porcs par des procédés combinant l'échange d'ions et le tamisage moléculaire. Ces mêmes techniques ou la chromatographie d'affinité sont également utilisées pour la purification de macromolécules nécessaires à certains vaccins : le virus poliomyélitique, la toxine du choléra et la tixine du tétanos. Ce développement (...) commence vraiment en 1956 avec la création des celluloses échangeuses d'ions par Peterson et Sober, utilisables dans la séparation des protéines.  1, record 1, French, - cellulose%20%C3%A9changeuse%20d%27ions

Record 1,  Textual support,  Spanish