Rødahl E
Scand J Immunol. 1985 Jan;21(1):93-8. doi: 10.1111/j.1365-3083.1985.tb01407.x.
Isopycnic ultracentrifugation is frequently applied for preparative isolation of macromolecules. Using bovine serum albumin (BSA)-anti-BSA antibody complexes as a model system, isopycnic banding of complexes was observed in CsCl, Nycodenz, and sucrose gradients. In CsCl gradients, free antigen or antibody could not be separated from the immune complexes. Variations in antigen to antibody ratio from equivalence and in the amount of complement present during complex formation resulted in zone broadening and banding at slightly lower densities in Nycodenz. This was not observed in sucrose. Serum immune complexes were isolated from patients with rheumatoid arthritis or ankylosing spondylitis. Banding of in vivo-formed immune complexes was observed more frequently in sucrose than in Nycodenz.
等密度超速离心法常用于大分子的制备性分离。以牛血清白蛋白（BSA）-抗BSA抗体复合物作为模型系统，在氯化铯、 Nycodenz和蔗糖梯度中观察到复合物的等密度区带。在氯化铯梯度中，游离抗原或抗体无法与免疫复合物分离。抗原与抗体比例偏离等价比例以及复合物形成过程中补体含量的变化，导致在Nycodenz中出现区带变宽和密度略低的条带。在蔗糖中未观察到此现象。从类风湿性关节炎或强直性脊柱炎患者中分离血清免疫复合物。与Nycodenz相比，在蔗糖中更频繁地观察到体内形成的免疫复合物的条带。
