Rash J M, Jerkunica I, Sgoutas D
Clin Chim Acta. 1979 Apr 16;93(2):283-94. doi: 10.1016/0009-8981(79)90101-3.
Addition of nonesterified fatty acids caused an apparent increase in unbound steroid present in supernatants in radioimmunoassays for steroids utilizing dextran-coated charcoal. Nonesterified fatty acid interference occurred at the initial binding interaction between steroid and its antiserum, and also at the step separating bound from unbound steroid. It was determined that nonesterified fatty acids, which had been added to radioimmunoassays, formed micelles and trapped steroids. The extent of the entrapment was inversely related to the number of polar groups in the steroid molecule, that is, hydrophobic steroids more easily interacted with the nonesterified fatty acid micelles. However, if the charcoal concentration were increased, the nonesterified fatty acid effect was eliminated for assays of polar steroids and greatly reduced for non-polar steroid assays.
在使用葡聚糖包被活性炭的类固醇放射免疫分析中，添加非酯化脂肪酸会导致上清液中未结合类固醇的明显增加。非酯化脂肪酸干扰发生在类固醇与其抗血清的初始结合相互作用阶段，以及分离结合态与游离态类固醇的步骤中。经测定，添加到放射免疫分析中的非酯化脂肪酸形成了微团并截留了类固醇。截留程度与类固醇分子中极性基团的数量呈负相关，也就是说，疏水性类固醇更容易与非酯化脂肪酸微团相互作用。然而，如果提高活性炭浓度，对于极性类固醇的分析，非酯化脂肪酸的影响会消除；对于非极性类固醇的分析，其影响会大幅降低。
