We have developed a new class of probes for homogeneous nucleic acid detection based on the proposed displacement hybridization. Our probes consist of two complementary oligodeoxyribonucleotides of different length labeled with a fluorophore and a quencher in close proximity in the duplex. The probes on their own are quenched, but they become fluorescent upon displacement hybridization with the target. These probes display complete discrimination between a perfectly matched target and single nucleotide mismatch targets. A comparison of double-stranded probes with corresponding linear probes confirms that the presence of the complementary strand significantly enhances their specificity. Using four such probes labeled with different color fluorophores, each designed to recognize a different target, we have demonstrated that multiple targets can be distinguished in the same solution, even if they differ from one another by as little as a single nucleotide. Double-stranded probes were used in real-time nucleic acid amplifications as either probes or as primers. In addition to its extreme specificity and flexibility, the new class of probes is simple to design and synthesize, has low cost and high sensitivity and is accessible to a wide range of labels. This class of probes should find applications in a variety of areas wherever high specificity of nucleic acid hybridization is relevant.

利用稳定的新型铕荧光络合物BHHCT与Eu3+标记羊抗人HBsAb和Eu3+标记BSA-SA，建立定量测定血清HBsAb的Eu3+ -BHHCT-HBsAb-TRFIA法和Eu3+ -BHHCT-BSA-SA-TRFIA法。结果表明，这两种方法最低检出值分别为0.2ng/mL和0.05ng/mL，标准曲线范围均为0-100ng/mL，批内变异系数CV均小于10%后者回收率为85%-115%用Eu3+ -BHHCT-BSA-SA-TRFIA法与ELISA法同时检测118份血清样品，结果表明前者的检出率比后者高。

目的建立改良分子信标2双重实时PCR同时检测霍乱弧菌和副溶血弧菌的快速方法，应用于霍乱监测、副溶血弧菌食物中毒的快速诊断和海产品检验。方法根据GenBank公布的霍乱弧菌肠毒素基因A亚单位（ctxA）和副溶血弧菌的耐热直接溶血毒素基因（TDH）的保守序列，分别设计引物和改良分子信标探针，以10种细菌作对照，建立双重实时PCR2改良分子信标检测体系，应用于副溶血弧菌食物中毒快速诊断和霍乱监测。结果改良分子信标2双重实时PCR 反应体系DNA灵敏度为102.4～166.6fgPμl，菌液灵敏度为32～64CFUPml或3～6CFUPPCR反应体系，无交叉反应。此反应体系同时检测40株副溶血弧菌和50株霍乱弧菌，均出现特异的荧光信号，两种细菌检测互不干扰。对3起细菌性食物中毒共48份样品和100份海产品进行检测，9份副溶血弧菌实时PCR阳性，其中7份副溶血弧菌细菌培养阳性，其余样品都为阴性。从样品处理到检测结果仅需1天时间。结论改良分子信标2双重实时PCR 检测体系快速、灵敏度高、特异性强，可用于霍乱和副溶血弧菌食物中毒的快速诊断，为食源性疾病的分子流行病学调查提供新的检测手段。

以荧光染料Eam和Joe分别标记野生型和突变型双链探针作为均相检测探针，以构建的DNA模板作为研究模型 采用固定波长差同步荧光分析法对PCR反应产物进行终点检测，通过对HFE基因C282Y点突变的检测，并以限制性内切核酸酶Rsa1证实，该方法是一种廉价、快速、可靠的筛查遗传性血色病基因C282Y突变的方法，该法可扩展到各种基因的突变检测。

A rapid and simple homogeneous fluorescence PCR assay was developed for the clinical diagnosis of infectious diseases based on a molecular beacon. The established method could reproducibly detect Mycobacterium tuberculosis at the 10 bacteria/mL level. The analytical specificity was tested with 14 strains of mycobacterium, four unrelated bacteria and 220 negative samples; no false positive results were obtained. A blind test was also performed to evaluate its performance in Mycobacterium tuberculosis diagnosis. The results showed that both the clinical sensitivity and the specificity were 100%, and that the detection limit was in the range of 1-10 bacteria/ml. A clinical study with 466 patient samples demonstrated that fluorescence PCR assay correlated well with smear (93.6%) and culture (98.4%) methods for positive samples. However, fluorescence PCR could detect positive samples (62.9%) more than smear (30.3%) and culture (31.4%), indicating a higher sensitivity of the present method than the traditional ones. The feasibility of this method was further approved by successful detection of Neisseria gonorrhoeae and Chlamydia trachomatis.