Institute of Transfusion Medicine, The Academy of Military Medical Sciences, Beijing 100850, China.
Toxicon. 2012 Jan;59(1):12-6. doi: 10.1016/j.toxicon.2011.10.003. Epub 2011 Oct 12.
The ultrasensitive bio-barcode amplification assay (BCA) technique was developed for the specific detection of the A chain of ricin toxin. The target antigen A chain was first captured by gold nanoparticles (GNPs) coated with polyclonal antibodies. Magnetic microparticles (MMPs) coated with A chain monoclonal antibody were then added to form a sandwich immuno-complex. After the immuno-complex was formed, signal DNA annealed to DNA strands covalently bound to the GNPs were released by heating and characterized by PCR and real-time fluorescence PCR. A detection limit of 1fg/ml was measured for A chain, six orders of magnitude more sensitive than that of conventional antigen-capture ELISA. The coefficient of variation (CV) of intra-assay and inter-assay ranged from 3.39% to 6.84%. The BCA can detect the A chain in milk and water mimic samples. In the following work it is demonstrated that this assay is a highly sensitive method for the detection of ricin proteins that could be adapted to measure other proteins.
超灵敏生物条码放大检测（BCA）技术被开发出来，用于特异性检测蓖麻毒素的 A 链。目标抗原 A 链首先被金纳米粒子（GNPs）捕获，这些 GNPs 上涂有多克隆抗体。然后加入涂有 A 链单克隆抗体的磁性微球（MMPs），形成三明治免疫复合物。免疫复合物形成后，通过加热释放与 GNPs 共价结合的 DNA 链上退火的信号 DNA，并通过 PCR 和实时荧光 PCR 进行表征。A 链的检测限为 1fg/ml，比传统的抗原捕获 ELISA 灵敏 6 个数量级。内测定和间测定的变异系数（CV）范围为 3.39%至 6.84%。BCA 可以检测牛奶和水模拟样品中的 A 链。在随后的工作中证明，该检测方法是一种高度敏感的蓖麻蛋白检测方法，可以适用于测量其他蛋白质。
