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采用反相悬浮包埋技术合成多分散的粒径在50目～300目的磁性葡聚糖微球（MDMS）。MDMS经环氧氯丙烷活化后，分别键合氨基乙酸、6-氨基己酸和乙二胺作为间隔臂，以碳二亚胺为偶联剂，分别偶联L-精氨酸甲酯、对氨基苯甲脒和胍基己酸配体，制备了5种磁性亲和吸附剂。研究了分散介质及其粘度和密度、有机相和水相的体积比、表面活性剂的用量、搅拌速度等因素对微球制备的影响。将所制备的磁性亲和吸附剂应用于尿激酶粗品的纯化，并讨论了偶联试剂和配体对尿激酶纯化效果的影响。通过测定，尿激酶的活性回收率为40.0%～60.7%、纯化倍数为14.9～32.8、吸附容量为89mg/L～121mg/L。

The reverse phase suspension and embedment technique were adopted to pre pare magnetic dextran microsphere (MDMS). The dispersion medium was mixture of some organic solvents. Span-80 was used as stabilizer. The aqueous dextran wit h magnetic fluid was suspended in dispersion medium with epichlorohydrin as cross -linking reagent. The mixture was stirred for 30 minutes at room temperature a nd then he ated at 70 ℃ for 4 hours, MDMS was thus obtained. MDMS was activated by epich lor ohydrin on which 6-aminohexanoic acid, glycine or ethylene diamine was bonded a s spacers. Then it was coupled with p-aminobenzamide, L-arginine methy l ester or guanidohexanoic acid and five magnetic affinity adsorbents were prepared. The M D MS was polydisperse particles with the size of 50-300 meshes and the con tent of Fe3O4 was about 6.2 per cent in the MDMS. Influence of some parameters suc h as visc osity and density of organic phase, the volume ratio of organic and aqueous phas e, the quantity of surfactant and stirring speed on preparing MDMS was studied. Magnetic affinity adsorbents were used to purify crude urokinase in a batch mode and the effect of coupling reagents and ligands on results of purification was disc ussed. The bioactivity recovery was 40.0 to 60.7 per cent, the purification- fold was between 14.9 and 32.8, and the adsorptive capacity varies from 89 mg to 121 mg per milliliter of adsorbent.