Havekes L, Hemmink J, de Wit E
Clin Chem. 1981 Nov;27(11):1829-33.
Radial immunodiffusion (RID) and rocket immunoelectrophoresis (RIE) are compared with respect to determination of LDL-bound apo B in plasma. Isolated VLDL could not enter a 15 g/L agarose gel when either technique was used. However, in the presence of plasma proteins, migration of VLDL into agarose was enhanced. Only when plasma samples were kept frozen before the assay was plasma VLDL unable to enter the agarose gel when RID was used. With RIE the contribution of plasma VLDL to the apo B determination under these conditions was not always negligible. Besides enhancing the entry of VLDL into the agarose, the presence of proteins also influences apo B immunoreactivity of LDL and VLDL. For measuring LDL-bound apo B directly in unfractionated plasma we recommend: (a) RID in 15 g/L agarose gel; (b) freezing the plasma samples before assay; (c) diluting the plasma samples in saline supplemented with protein in the same concentration as is present in plasma (70 g/L); and (d) using plasma as the assay standard.
就血浆中低密度脂蛋白（LDL）结合的载脂蛋白B（apo B）的测定而言，对单向免疫扩散（RID）和火箭免疫电泳（RIE）进行了比较。使用这两种技术中的任何一种时，分离出的极低密度脂蛋白（VLDL）都无法进入15 g/L的琼脂糖凝胶。然而，在血浆蛋白存在的情况下，VLDL向琼脂糖中的迁移会增强。仅当在测定前将血浆样本冷冻时，使用RID时血浆VLDL才无法进入琼脂糖凝胶。对于RIE，在这些条件下血浆VLDL对apo B测定的贡献并非总是可以忽略不计。除了增强VLDL进入琼脂糖的能力外，蛋白质的存在还会影响LDL和VLDL的apo B免疫反应性。为了直接在未分级的血浆中测量LDL结合的apo B，我们建议：（a）在15 g/L琼脂糖凝胶中进行RID；（b）在测定前冷冻血浆样本；（c）用与血浆中相同浓度（70 g/L）的补充了蛋白质的盐水稀释血浆样本；以及（d）使用血浆作为测定标准。
