直接竞争酶联免疫吸附法检测虾过敏蛋白

目的:建立酶标抗原的直接竞争酶联免疫吸附法(dcELISA)检测食品中虾过敏蛋白,为食品过敏诊断试剂的开发和应用提供理论基础。方法:提取虾主要过敏蛋白,免疫小鼠制备抗虾过敏蛋白多克隆抗体,辣根过氧化物酶(HRP)标记抗原,建立酶标抗原的dcELISA检测虾过敏蛋白。结果:所建立的dcELISA法最低检测限为3.94ng/mL,标准曲线在0.12～128.86ng/mL范围内线性良好,批内和批间变异系数分别为6.16%和2.73%,回收率为82%～98%。结论:该方法具有良好的特异性、敏感性和稳定性,为进一步研制检测虾过敏蛋白的ELISA试剂盒提供有效的方法。      

沙丁胺醇直接竞争ELISA 法快速测定

建立沙丁胺醇的直接竞争ELISA(dcELISA)快速检测方法,采用高碘酸钠法制备辣根过氧化物酶标记沙丁胺醇单克隆抗体,棋盘滴定法确定包被抗原质量浓度和抗体稀释倍数,通过单因素试验,考察反应体系中表面活性剂、离子浓度、甲醇体积分数、pH 值因素对dcELISA 性能的影响,确定最优检测条件,同时考察方法的特异性。结果表明：酶标抗体克分子比为2.1 时偶合物的滴度最高,最佳反应条件为包被抗原质量浓度1μg/mL,酶标抗体稀释2560 倍,0.01mol/L、pH7.4 的磷酸盐抗体稀释液(PBS)中含体积分数0.05% 的Tween-20、0.5mol/L NaCl溶液和体积分数5% 的甲醇时dcELISA 具有最高的灵敏度和最好的稳定性,所建立方法的IC50 为10.3ng/mL,检测限为0.049ng/mL,线性范围0.3～76.30ng/mL,批内变异系数13.8%,批间变异系数为22.38%,与克伦特罗交叉反应率为321.18%,与溴布特罗交差反应率为29.09%,与其他结构类似物没有明显交叉反应。本研究所建立的dcELISA 可用于沙丁胺醇和克伦特罗的多残留检测。     

脱氧雪腐镰刀菌烯醇(DON)直接竞争ELISA方法的建立

利用前期制备得到的DON酶标抗原(辣根过氧化物酶标记)以及抗DON抗体,建立检测食品中DON含量的直接竞争ELISA方法。该方法的检测范围1～100ng/mL,灵敏度达0.56ng/mL,半数抑制浓度IC50为10ng/mL;与DON类似物T-2毒素的交叉反应率为12%;玉米淀粉样品回收率在80.2%～91.1%之间,平均批间变异<15%,平均批内变异<3%。     

直接竞争化学发光酶免疫法检测猪肉中磺胺嘧啶

建立一种检测猪肉中磺胺嘧啶的简便、快速、高特异性的直接竞争化学发光酶免疫法。采用改良的过碘酸钠法制备酶标抗体,以辣根过氧化物酶催化鲁米诺-过氧化氢作为化学发光体系。经优化该方法检测条件为：利用柠檬酸缓冲液稀释抗原包被质量浓度为0.8μg/mL,酶标抗体2000倍稀释,竞争反应25min;所建立的方法分析灵敏度为2.96ng/mL,批内变异系数小于8.32%,批间变异系数小于13.4%,以猪肉为样品的分析回收率为75.6%～103.7%,与其他结构类似物未见明显交叉,所建立的标准曲线相关系数为0.9922、检测线性范围为4.14～244ng/mL、检测时间为25min,可在实际生产中应用。     

直接竞争化学发光酶免疫法检测谷物中的伏马菌素B1

建立1种检测谷物中伏马菌素B1的直接竞争化学发光酶免疫方法。该方法的最佳检测条件为:抗原包被质量浓度0.4μg/mL,酶标抗体3000倍稀释,竞争反应时间20min;检测限为0.13ng/mL,半抑制浓度(IC50)为1.43ng/mL,批内变异系数2.4%,批间变异系数9.2%,以玉米为样品的加标回收率达到100.2%～115.4%。谷物盲样的检测结果显示,该方法与酶联免疫吸附检测试剂盒、高效液相色谱检测结果的相关系数分别为0.9793、0.9851,三者之间无显著性差异,所建立的直接竞争化学发光酶免疫方法可用于谷物样品中伏马菌素B1的大规模快速筛查。     

基于单克隆抗体的双酚A间接竞争酶联免疫分析法的建立

为建立一种简便、快速、准确的双酚A检测方法,采用活性酯法将双酚酸与牛血清蛋白、卵清蛋白偶联制备人工抗原免疫BALB/c小鼠。选择抗血清效价和灵敏度高的BALB/c小鼠,采用聚乙二醇法制备杂交瘤细胞,获得一株可分泌双酚A单克隆抗体的杂交瘤细胞株。通过方阵滴定和反应条件优化,建立一种基于单克隆抗体的双酚A间接竞争酶联免疫分析法。该检测方法在0.5 ng/mL～50 ng/mL内有良好的线性关系,最低检测限IC10为0.5 ng/mL,半数抑制率IC50为16.65 ng/mL,水样中加标回收率为89.72%～105.25%。该单克隆抗体效价高、特异性强,该检测方法灵敏度高。     

基于单克隆抗体的双酚A半抗原直接包被的酶联免疫吸附法的建立

传统的人工抗原包被酶联免疫吸附法(ELISA)依赖疏水相互作用将人工抗原与酶标板结合,会影响半抗原的呈现与识别,且多采用多克隆抗体为检测抗体,这些均会导致检测灵敏度下降和标准化难度增大。该研究选择双酚酸(BVA)作为双酚A(BPA)的半抗原与蛋白质偶联制备人工抗原免疫BALB/c小鼠,获得一株可分泌BPA单克隆抗体(MAb)的杂交瘤细胞株。利用3-氨丙基三乙氧基硅烷硅化处理酶标板,将BVA直接包被在酶标板上,建立了一种基于MAb的半抗原直接包被的BPA间接竞争ELISA法。该检测方法最低检测限IC10为0.29 ng/mL,半数抑制率IC50为5.4 ng/mL,水样中加标回收率为94.04%~102.31%。与人工抗原包被BPA ELISA检测方法(IC10:0.5 ng/mL,IC50:16.65 ng/mL,水样中加标回收率为89.72%~105.25%)相比,检测灵敏度显著性提高。     

基于虾类原肌球蛋白共同表位肽抗体的过敏原检测方法

目的建立一种能够同时检测多种虾原肌球蛋白的方法。方法通过合成不同虾类的共同表位肽,制备能够识别多种虾类原肌球蛋白的共同表位肽多克隆抗体,建立快速灵敏的虾类原肌球蛋白酶联免疫检测方法。结果该检测方法在4.79～1400 ng/mL的浓度范围内线性关系良好,其线性回归方程为Y=-19.083X+98.303(R~2=0.9813),最低检出限(IC_(10))为1.85 ng/mL;样品加标回收率在94.37%～103.45%之间;该检测方法与软体动物的原肌球蛋白有交叉反应,与鱼肉蛋白、牛奶、花生蛋白等无交叉反应;批内变异系数为3.4%～9.1%,板间变异系数为12.9%～19.6%,贮藏试验显示该酶联免疫试剂盒可以在4℃下保存6个月以上,能够应用于食品中虾类过敏原的检测。结论采用共同表位抗体,成功建立了基于酶联免疫的过敏原检测方法。     

黄曲霉毒素B1直接竞争化学发光酶免疫分析法的建立

以鲁米诺-辣根过氧化物酶-过氧化氢为检测体系,建立一种检测黄曲霉毒素B1的直接竞争化学发光酶免疫法。经优化,该方法的最佳反应条件为抗体包被为0.0625μg/mL;黄曲霉毒素B1酶标抗原（1mg/mL）稀释10000倍;0.01mol/L磷酸盐缓冲液（pH7.5）。本方法的IC50为0.062ng/mL;检出限为0.01ng/mL;线性范围0.017⁰.215ng/mL,批内和批间相对标准偏差均小于15%。食用油样品的添加回收率为88.7%⁹8%,通过对比实验证实,该方法与ELISA方法相关性良好,可用于实际样品中黄曲霉毒素B1的大规模快速筛查。      

化学发光酶联免疫法检测苏丹红Ⅰ

为检测食品中苏丹红Ⅰ残留,建立间接竞争化学发光酶联免疫分析（chemi luminescent enzymeimmunoassay,CLEIA）法。通过优化包被抗原中本抗原与载体物质的量比、包被抗原质量浓度、抗体稀释比例,建立竞争抑制曲线。线性范围为0.156～5 ng/mL,最低检测限为0.078 9 ng/mL,IC50为0.679 ng/mL。CLEIA回收率为75.08%～112.18%,变异系数为8.89%～15.61%;通过与酶联免疫吸附（enzyme-linked immunosorbent assay,ELISA）法进行比较,在相同抗原抗体质量浓度条件下,CLEIA法测定的IC50较ELISA方法降低30%,具有较高的灵敏度。     

直接竞争ELISA法快速测定水产品中6种氟喹诺酮类药物

采用过碘酸钠法将抗环丙沙星单克隆抗体（MAb-CIP）与辣根过氧化物酶（HRP）偶联制备酶标抗体MAbCIP-HRP,建立了检测水产品中6种氟喹诺酮类药物残留的直接竞争酶联免疫吸附分析方法（dcELISA）,考察了包被原浓度、竞争反应时间和有机溶剂等因素对方法灵敏度的影响。结果表明:在优化的反应条件下,所建立的dcELISA针对环丙沙星、恩诺沙星、诺氟沙星、培氟沙星、沙拉沙星和双氟沙星6种氟喹诺酮类药物的检测限（LOD）均不超过0.5ng/mL,线性范围（IC20^IC80）在1.0¹2.1ng/mL之间;对虾、鳗鲡和鲫鱼三种水产样品中添加5.0、10.0和20μg/kg时,加标回收率为70.4%¹04.1%,相对标准偏差为5.0%¹4.7%;本方法可用于水产品中氟喹诺酮类（FQs）药物多残留的快速测定。      

直接竞争ELISA法检测蜂蜜中氯霉素残留

建立蜂蜜中氯霉素直接竞争酶联免疫吸附测定（enzyme-linked immunosorbent assay,ELISA）检测方法。以抗氯霉素单克隆抗体为包被原,氯霉素-辣根过氧化物偶联物为标记物,3,3’,5,5’-四甲基联苯胺作显色底物,对其主要影响因素,如标准品稀释液、包被温度、包被抗体稀释倍数等6?个因素进行优化,同时还对该方法的准确性和稳定性进行考察。结果表明：所建立的直接竞争ELISA标准曲线方程式为y=－17.425x＋97.509,相关系数R2为0.991?2,IC50值为0.63?ng/mL,检出限和线性检测范围分别为（0.04±0.01）ng/mL和0.10～4.17?ng/mL;另外整个检测反应过程耗时约为40?min。蜂蜜样品的检出限和定量限分别为0.15?ng/g和0.33?ng/g,添加回收率在97.58%～100.94%之间,批内变异系数和批间变异系数均小于11%,表明该方法具有高精确度和稳定性。     

虾蛋白过敏实验动物模型的建立

以卵白蛋白为阳性对照,以平衡盐溶液(PBS)为阴性对照,观察虾蛋白的全身过敏反应。同时,观察虾蛋白对致敏豚鼠离体回肠平滑肌过敏性收缩反应(Schultz-Dale 反应)的影响,以建立虾蛋白过敏实验动物模型。结果显示,用0.01～2g/100mL 卵白蛋白致敏并激发后,100% 豚鼠呈全身过敏反应阳性,0.1g/100mL 卵白蛋白组的豚鼠100% 死亡。相似质量浓度虾蛋白(0.01～1g/100mL)的全身过敏反应与卵白蛋白相近(与卵白蛋白组比较,P ＞ 0.05);Schultz-Dale 反应的实验结果与全身过敏反应结果相似。由此,初步建立虾蛋白过敏实验的动物模型。     

An Enhanced Direct Competitive Immunoassay for the Detection of Kanamycin and Tobramycin in Milk Using Multienzyme-Particle Amplification

Kanamycin (Kan) and tobramycin (Tob) are widely found in many foods of animal origin, including milk. More rapid, simple, and sensitive methods are urgently needed to monitor antibiotic residues in milk. An enhanced direct competitive enzyme-linked immunosorbent assay (dcELISA) based on gold nanoparticles (AuNPs)/horse radish peroxidase-Kan (HRP-Kan) was developed. A monoclonal antibody (Mab) against Kan was developed by classic hybridoma technology. The Mab had higher cross-reactivity with Tob (99.07%) and no cross-reactivity with other related antibiotics (<?0.5%). A novel multienzyme probe was synthesized based on AuNPs modified using HRP-Kan. The Mab against Kan, fixed by a goat anti-mouse antibody, was competitively bound by AuNPs/HRP-Kan and Kan in samples. After optimization, the limit of detection of the enhanced dcELISA was 0.022 ng/mL, representing a fivefold improvement when compared to that of conventional dcELISA (0.13 ng/mL). The recoveries of Kan and Tob in milk samples varied from 81.0 to 121.0% and 86.4 to 123.9%, respectively. Kan or Tob was found to be present at concentrations of 0.352–0.548 ng/mL in five milk samples from local markets. The results by the enhanced ELISA and UPLC-MS/MS had good correlation. It was suggested that the enhanced dcELISA, based on AuNPs/HRP-Kan, has higher sensitivity and reliable reproducibility, and thus, this could be used to detect trace contaminants.     

Sensitive enzyme-linked immunosorbent assay and gold nanoparticle immunochromatocgraphic strip for rapid detecting chloramphenicol in food

Antibody specific to chloramphenicol (CAP) was produced from rabbit that had been immunized with CAP-keyhole limpet hemocyanin (KLH). Using the antibodies, we established a sensitive direct competitive enzyme-linked immunosorbent assay (dcELISA) and a gold nanoparticle immunochromatographic strip (immunostrip) for detection CAP in food samples. In the dcELISA, CAP at levels of 0.15 ng/ml causes 50% inhibition (IC₅₀) of the binding of CAP-horseradish peroxidase to the antibodies. The overall analytical recoveries of CAP (0.25–100 ng/g) added to the honey or milk samples in the dcELISA were 81.9 and 73.7%, respectively. Onsite determination of CAP was accomplished by immunostrips with a detection limit of 0.5 ng/ml and completed within 10 min. Carefully studying 10 honey and 6 milk samples using the dcELISA and immunostrip indicated that all examined samples were negative for CAP. The presented dcELISA and immunostrip methods are sensitive enough for the rapid determination of CAP in the samples.     

Indirect competitive enzyme-linked immuno-sorbent assay (ELISA) for nitroimidazoles in food products

Ronidazole was used as the starting material to prepare an immunogen and coating antigen. An anti-nitroimidazole monoclonal antibody was produced and an indirect competitive ELISA was established to detect nitroimidazole compounds in food products. The IC(50) values were determined to be 0.20 ng/ml for metronidazole, 4.0 ng/ml for tinidazole, 0.17 ng/ml for dimetridazole and 0.24 ng/ml for ornidazole. Considering that nitroimidazoles were commonly used as veterinary drugs, nitroimidazole residues in food products of animal origin were detected by the method. The coefficient of variation for nitroimidazoles determination in contaminated chicken, chicken liver and shrimp were all <14% and the recovery rate was in the range 74.0-90.6%. The results proved that the developed method was successful in detecting nitroimidazoles in food products.     

基于单链抗体的呋喃唑酮酶联免疫检测方法的建立

目的:为快速检测呋喃唑酮(furazolidone,FZD)在动物性食品中的残留量。方法:基于单链抗体的间接竞争酶联免疫吸附实验法建立了FZD检测方法。结果:最佳抗原工作质量浓度为2μg/m L,最佳抗体稀释倍数为1∶500,一抗最佳反应时间为60 min,二抗最佳反应时间为45 min,四甲基联苯胺最佳显色时间为20 min。FZD检测试剂盒在10~100 ng/m L范围具有较好的线性关系,IC50值为13.01 ng/m L,检出限为1.28 ng/m L,回收率为73.38%~84.52%。结论:与抗FZD单克隆抗体相比,所建立的检测试剂盒检测范围更广,且具有很高的灵敏度以及很好的特异性和稳定性。     

保健酒中萘普生免疫学检测方法的建立

萘普生是疗效显著但有一定副作用的非甾体抗炎药物,近期频繁发现不法生产者在抗风湿保健酒中添加萘普生增加治疗效果,这种现象对消费者健康构成威胁。为了究建立快速检测萘普生的免疫学方法, 本文以活泼酯法将萘普生分别连接到BSA制备免疫抗原,连接到OVA上制备检测抗原。用免疫抗原免疫家兔制备多克隆抗体,配合检测抗原经条件优化建立竞争抑制酶联免疫吸附检测方法。实验结果表明,检测体系IC50值为23.0 ng/mL,最低检测限为3.1 ng/mL,检测保健酒中萘普生加标回收率在87.3~102.1%,变异系数小于8.9%,与8种相关药物交叉反应率都小于0.05%。且与用ELISA方法与HPLC检测市售保健酒,1例阳性和19例阴性结果全部吻合。因此,本文所建立的免疫学检测萘普生的实验方法,具有高灵敏度和特异性,能够满足保健酒萘普生快速筛选的需要。     

Indirect competitive enzyme-linked immuno-sorbent assay (ELISA) for nitroimidazoles in food products

Ronidazole was used as the starting material to prepare an immunogen and coating antigen. An anti-nitroimidazole monoclonal antibody was produced and an indirect competitive ELISA was established to detect nitroimidazole compounds in food products. The IC₅₀ values were determined to be 0.20?ng/ml for metronidazole, 4.0?ng/ml for tinidazole, 0.17?ng/ml for dimetridazole and 0.24?ng/ml for ornidazole. Considering that nitroimidazoles were commonly used as veterinary drugs, nitroimidazole residues in food products of animal origin were detected by the method. The coefficient of variation for nitroimidazoles determination in contaminated chicken, chicken liver and shrimp were all <14% and the recovery rate was in the range 74.0–90.6%. The results proved that the developed method was successful in detecting nitroimidazoles in food products.