葡聚糖,分子量40,000Dextran

• 产品编号：0210150550      品牌：MP       原厂货号：0210150550
• 产品分类：生化和细胞分析 > 标签、标记试剂盒 > 生物偶联物 > 葡聚糖偶联物
• 应用分类：暂定分类 > 标签蛋白的分离

描述：

Description: Dextran is a high molecular weight polymer of anhydroglucose. It is composed of approximately 95% alpha-D-(1-->6) linkages. The remaining a(1-->3) linkages account for the branching of dextran.^8,23,25 Conflicting data on the branch lengths implies that the average branch length is less than three glucose units.^19,20 However, other methods indicate branches of greater than 50 glucose units exist.^5,24 Native dextran has been found to have a molecular weight in the range of 9 million to 500 million.^3,4,9 Lower molecular weight dextrans will exhibit slightly less branching²⁰ and have a more narrow range of molecular weight distribution. Dextrans with molecular weights greater than 10,000 behave as if they are highly branched. As the molecular weight increases, dextran molecules attain greater symmetry.^12,24,26 Dextrans with a molecular weight of 2,000 to 10,000 dextran molecules exhibit the properties of an expandable coil.¹² At molecular weights below 2,000, dextran is more rod-like.¹⁰ The molecular weight of dextran is measured by one or more of the following methods: low angle laser light scattering², size exclusion chromatography¹³, copper-complexation²⁷, and anthrone reagent⁴ colormetric reducing-end sugar determination and/or viscosity.¹² During preparation, fractionation can be accomplished by size exclusion chromatography¹³ or ethanol fractionation in which the largest molecular weight dextrans precipitate first.¹⁷

Dextran solutions have been used as plasma extenders.^1,28 Solutions of 10% dextran (MW ~40,000) exert a slightly higher colloidal osmotic pressure than plasma proteins. A 10% Dextran (MW ~40,000) solution in 0.9% sodium chloride or 5% glucose has reported to be used as a short-term plasma extender for post-operative thrombo-embolic disorders. After infusion, approximately 70% dextran (MW ~40,000) is excreted in the urine unchanged after 24 hours. A small amount is eliminated in the feces. The remaining dextran is slowly metabolized to glucose. A 6% dextran (MW ~70,000) solution exerts a colloidal osmotic pressure similar to that of plasma proteins. Dextrans with molecular weights greater than 50,000 tend to slowly diffuse across the capillary wall and are slowly metabolized to glucose. Approximately 50% of infused dextran (MW ~70,000) is excreted unchanged in the urine in 24 hours.²⁸

Colloidal solutions containing dextran (MW ~250,000) have been used to isolate aggregated platelets²¹, leukocytes⁶ and lymphocytes¹⁴ in blood by centrifugation. Dextran (MW ~40,000) has been used for the isolation of intact nuclei.¹⁶

Dextran can be used to enhance the precipitation and sensitivity of antibody-antigen complexes in immuno-diffusion applications. Dextran (MW ~80,000) was infused into an immunoelectrophoresis gel at a maximum of 80 mg/ml.¹⁵ Dextrans (MW ~250,000 to 2 million) have also been used in similar applications.⁷

At lower concentrations, dextrans (MW ~10,000 to 40,000) have been used to inhibit platelet aggregation.¹¹

Dextran (MW ~400,000 to 500,000) can be used as long and hydrophilic spacer arms to improve the performance of immobilized proteins acting on macromolecules.

葡聚糖

用途：清除游离基、抗辐射、溶解胆固醇，预防高脂血症作用及抵抗滤过性病毒、真菌、细菌等引起的感染。葡聚糖制成的凝胶常用来进行生化分离，如柱层析。

原厂资料：

注意事项：

Neutral aqueous dextran solutions can be sterilized by autoclaving at 110-115°C for 30 to 45 minutes. Dextran can be hydrolyzed by strong acids at high temperatures. The terminal reducing end group of dextran can be oxidized in alkaline solutions.