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Guiseley K. B. Kirkpatrick F. H. Provonchee R. B. Dumais M. M. Nochumson S. 《Hydrobiologia》1993,(1):505-511
Hydrobiologia - Commercial agarose can be separated into two components by fractional precipitation using alcohols or glycols. The less soluble component has a much higher gel strength and lower... 相似文献
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Donald W. Renn Gertrudes A. Santos Lisa E. Dumont Charles A. Parent Norman F. Stanley Dimitri J. Stancioff Kenneth B. Guiseley 《Carbohydrate polymers》1993,22(4):247-252
β-Carrageenan, essentially devoid of ester sulfate, was isolated from the hot aqueous extracts of alkali-modified Eucheuma gelatinae, Eucheuma speciosa, and Endocladia muricatum by precipitating the more anionic moieties with a quaternary ammonium salt, isolating the fractions that did not precipitate, then treating these with an anion-exchange cellulose. The β-carrageenan was characterized by chemical analysis, optical rotation, and NMR. Gelling was found to be ion-independent, with Tg = 31–33°C and Tm = 63–70°C. Specific optical rotations of the isolated β-carrageenan samples were more positive than the κ-, λ-, and ι-carrageenans with which they were compared, while agarose, its stereoisomer, exhibited a negative specific rotation. Electrophoresis gels made from β-carrageenan were used to separate DNA fragments which exhibited faster migration than on an agarose gel of comparable concentration, indicating that β-carrageenan has a less restrictive pore structure. 相似文献
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