Niskanen A, Lindroth S
Appl Environ Microbiol. 1976 Dec;32(6):735-40. doi: 10.1128/aem.32.6.735-740.1976.
Staphylococcal enterotoxin A (SEA) was labeled by the chloramine-T method with 125I to a specific activity of 68 to 300 muCi per mug of SEA and with 131I to specific activity of 8 to 218 muCi per mug of SEA. SEA was partially damaged and aggregated during the labeling and storage. The damage seemed not to be greatly dependent on the specific activity of labeled entertoxin. Crossed immunoelectrophoresis showed two antigenically active and three inactive components in the ascending part of the labeled enterotoxin peak during fractionation by gel chromatography. During storage at 4 degrees C, the antigenic activity of label decreased faster when labeling had been with 131I than when with 125I. The antigenic activity of labeled SEA was lowered remarkably in the ascending part of the protein peak. Greatest release of radioiodine during storage was in the same part of protein peak. According to these results, the most suitable label for radioimmunoassay is obtained from the descending part of protein peak.
用氯胺 - T法分别用¹²⁵I和¹³¹I标记葡萄球菌肠毒素A（SEA），¹²⁵I标记的SEA比活度为每微克SEA 68至300μCi，¹³¹I标记的SEA比活度为每微克SEA 8至218μCi。在标记和储存过程中，SEA发生了部分损伤和聚集。这种损伤似乎在很大程度上不依赖于标记肠毒素的比活度。在凝胶色谱分级分离过程中，交叉免疫电泳显示在标记肠毒素峰的上升部分有两个抗原活性成分和三个无活性成分。在4℃储存期间，用¹³¹I标记时标记物的抗原活性下降速度比用¹²⁵I标记时更快。标记SEA的抗原活性在蛋白质峰的上升部分显著降低。储存期间放射性碘的最大释放发生在蛋白质峰的同一部分。根据这些结果，放射免疫测定最合适的标记物取自蛋白质峰的下降部分。
