Minobe S, Nawata M, Watanabe T, Sato T, Tosa T
Department of Biochemistry, Tanabe Seiyaku Company, Limited., Osaka, Japan.
Anal Biochem. 1991 Nov 1;198(2):292-7. doi: 10.1016/0003-2697(91)90427-u.
The LAL test is inhibited or enhanced by many substances. To overcome these problems, we have developed a specific endotoxin assay method using an ultrafiltration unit, a fluorometric LAL reagent, and immobilized histidine (which is a specific adsorbent for endotoxins). This method is composed of two steps. The first step is the adsorption of endotoxins. Using immobilized histidine, endotoxins are quantitatively adsorbed on the adsorbent, and the adsorbed endotoxins are separated from LAL-inhibiting or -enhancing substances by the ultrafiltration unit. The second step is the reaction of adsorbed endotoxins with the LAL reagent. The endotoxins adsorbed on immobilized histidine are directly reacted with the LAL reagent in a filter cup and show enough activity for assay. The reproducibility and the accuracy of this method are high, and the recovery of endotoxins from a sample solution is more than 95%. The new endotoxin assay method using immobilized histidine can be utilized for the determination of endotoxins in a solution containing LAL-inhibiting or -enhancing substances such as amino acids and antibiotics instead of requiring employment of the more common gel-clot technique.
许多物质会抑制或增强鲎试剂检测（LAL 检测）。为克服这些问题，我们开发了一种特定的内毒素检测方法，该方法使用超滤装置、荧光鲎试剂和固定化组氨酸（一种内毒素特异性吸附剂）。此方法由两个步骤组成。第一步是内毒素的吸附。利用固定化组氨酸，内毒素被定量吸附在吸附剂上，吸附的内毒素通过超滤装置与抑制或增强鲎试剂的物质分离。第二步是吸附的内毒素与鲎试剂反应。吸附在固定化组氨酸上的内毒素在滤杯中直接与鲎试剂反应，并显示出足够的活性用于检测。该方法的重现性和准确性都很高，样品溶液中内毒素的回收率超过 95%。使用固定化组氨酸的新型内毒素检测方法可用于测定含有抑制或增强鲎试剂的物质（如氨基酸和抗生素）的溶液中的内毒素，而无需采用更常用的凝胶凝块技术。
