应用生物素-链霉亲和素的时间分辨荧光免疫分析检测玉米赤霉烯酮

采用基于生物素（Biotin）-链霉亲和素（Strepavidin）的时间分辨荧光免疫分析（TRFIA）技术建立了快速灵敏的玉米赤霉烯酮（ZEN）检测方法。以strepavidin包被板条，加入生物素化的ZEN—BSA，结合在板条上的ZEN—BSA与标准／样本中的游离ZEN共同竞争限量的抗ZEN单克隆抗体，用稀土离子Eu“标记的羊抗鼠IgG进行示踪，建立了间接竞争的ZEN-TRFIA。该方法的检测灵敏度为0．2ng／ml，测量范围是0．2～200．0ng／ml，批内、批间变异系数分别为5．7％和8．3％，平均回收率为91．1％。与玉米赤霉醇的平均交叉反应是12．3％，与赭曲霉素A、脱氧雪腐镰刀菌烯醇、黄曲霉素B1无交叉反应，说明该方法的特异性较好。相关试剂在4℃放6个月后各检测参数基本无变化，说明该方法稳定。样品同时用ZEN—TRFIA和商品ELISA试剂盒测定样品ZEN含量，两者的相关系数为0．9664，说明该方法测量准确。ZEN—TRFIA具有测量准确、检测灵敏度高、检测范围宽、操作简便、标记物稳定等优点，适合于ZEN大量筛查的应用。

广州市天河区大气污染与居民外周血P_（53）蛋白关系研究

应用ＬＳＡＢ（链菌素－生物素标记法）检测了３组不同人群外周血中Ｐ５３蛋白表达的水平．结果表明，肿瘤病人组淋巴细胞ｐ５３蛋白表达水平最高，污染区居民组居中，正常对照组最低．经方差分析，３组差别有显著性意义（Ｐ＜０．０５）．

Ultrasonic-assisted synthesis and strepavidin conjugation of amino-magnetic nanoparticles

MNPs are widely used in biotechnology, magnetic resonance imaging, catalysis and other areas. In this paper, we propose a simple, quick, inexpensive and efficient way to prepare amino-MNPs with sonication-assisted process. The amino-MNPs prepared by hydrolyzing TEOS and APS were characterized by SEM, TEM and FTIR. Conjugation of SA and amino-MNPs was also studied. The biotin bound capacity of prepared SA coated amino-MNPs was 1.824 nmol/mg, which well meet the need of biological application.