免疫磁珠-PCR试纸条快速检测食品中牛源成分方法的建立

建立食品中牛成分快速检测的免疫磁珠-PCR试纸条方法。免疫磁珠提取食品中核酸,设计牛特异性引物,建立牛成分快速检测的PCR-试纸条方法。验证方法的特异性、灵敏度和稳定性。该方法检测灵敏度0.01%,能够从食品中扩增出561 bp特异性DNA片段。建立的食品中牛成分检测的免疫磁珠-PCR试纸条法特异性好,灵敏度高,简便,快速,是食品中牛成分检测的有效方法。     

PCR-核酸试纸条法检测食品中假结核耶尔森菌

目的 建立一种基于PCR-核酸试纸条技术快速检测食品中假结核耶尔森菌的方法。方法 将10株假结核耶尔森菌株和9株其他耶尔森氏菌及18株来源菌株作为实验菌株进行特异性实验; 通过纯菌液计数、干扰菌实验检测进行灵敏度验证。结果 DNA检测可达到10?3 μg/mL, 25 g样品加菌实验灵敏度可达 100 CFU/25 g, 添加10倍干扰菌不会降低检测灵敏度。利用建立方法对市场购买的食品进行筛查并与国标方法进行比较, 建立方法的灵敏度优于国标方法。结论 该方法检测结果准确, 灵敏度高, 适用于检测食品中假结核耶尔森菌。     

核酸试纸条法检测食品中小肠结肠炎耶尔森菌

建立一种基于聚合酶链反应(polymerase chain reaction,PCR)试纸条技术的快速检测小肠结肠炎耶尔森菌的检测方法。对26株小肠结肠炎耶尔森氏菌标准菌株及26株其他菌属标准菌株进行特异性试验,利用纯菌稀释及样品添加进行灵敏度试验。利用建立方法对市场购买的食品进行筛查并与国标方法进行比较。建立的方法 DNA检测灵敏度达到10~(-3)μg/mL,样品加菌试验检测灵敏度可达100 CFU/25 g。     

环介导等温扩增结合免疫层析试纸条快速检测羊肉及其制品中的鸭源成分

为实现肉及肉制品中掺假成分的快速检测,本文将环介导等温扩增技术(loop mediated isothermal amplification,LAMP)与免疫层析试纸条(immunochromatographic test strip,ICTS)相结合,建立了一套可在羊肉及其制品中特异并灵敏地检测出鸭源性成分的方法.根...     

免疫层析试纸条信号放大技术研究进展

免疫层析试纸条（Immunochromatographic Test Strip, ICTS）是建立在毛细管层析技术和抗原-抗体特异性反应基础上的一种检测技术,具有成本低、操作简单、不需要专业人员、分析时间短、特异性强和结果肉眼可见等特点,目前被广泛应用于食品安全快速检测中。基于传统球状金纳米材料的ICTS是目前最为常见的方法。但是传统方法仅能实现定性或半定量检测,其低检测灵敏度无法满足现在的检测需求。因此,利用信号放大技术来提高ICTS的灵敏度越来越受到人们的关注。本文总结了ICTS的信号放大策略并提出了未来的发展方向,以期为食品安全快速检测技术的发展提供技术参考。     

草甘膦胶体金免疫层析试纸条的研制

基于竞争抑制免疫层析原理,开展茶叶中草甘膦快速检测试纸条的研制.采用柠檬酸三钠还原氯金酸制备了 20 nm胶体金颗粒,然后以胶体金为标记物制备草甘膦单克隆抗体-胶体金偶联物,以硝酸纤维素膜为固相载体,包被草甘膦半抗原-卵清蛋白偶联物为检测线、羊抗兔二抗为质控线,建立草甘膦的胶体金快速检测试纸条.同时优化了胶体金最适pH...     

免疫层析试纸条在食品安全检测中的应用

随着现代食品安全问题的日益凸显,研发快速、准确、低成本的食品安全检测方法具有重要意义。免疫层析试纸条作为一种常用的检测工具,已被广泛应用于食品安全领域。本研究旨在探究免疫层析试纸条在食品安全检测中的应用潜力。通过对相关文献进行综述,可知免疫层析试纸条具有高度的选择性和敏感性,能够迅速检测出食品中的有害物质和致病菌。此外,免疫层析试纸条还具有操作简便、不需要复杂仪器设备、检测周期短等优点,适用于在实验室和现场进行食品安全快速检测。     

基于胶体金免疫层析技术的赤霉素快筛试纸条的研制

研制快速检测豆芽中赤霉素的快筛试纸条。采用免疫层析技术,以胶体金为标记物制备赤霉素单克隆抗体-胶体金偶联物,以竞争抑制模式制备赤霉素胶体金免疫层析试纸条。该试纸条对豆芽中赤霉素的检测限为100 μg/kg,灵敏度为98%,特异性为97%,假阴性率为2%,假阳性率为3%。该方法操作简便,具有较高的灵敏度和特异性,可广泛应用于豆芽中赤霉素残留的现场筛查和检测。     

免疫层析试纸条技术在食品安全领域的研究进展

免疫层析试纸条技术(Immunochromatographic Test Strip,ICTS)结合了色谱分析的分离能力和免疫分析的特异性,具有操作简单,检测快速以及价格低廉的特点,已成为食品安全快速检测领域研究的热点.传统的ICTS是以胶体金作为信号标记材料,但是胶体金试纸条检测灵敏度较低,只适用于定性和半定量检测....     

呋喃唑酮代谢物单克隆抗体和胶体金免疫层析试纸条的研制

本研究旨在建立一种快速检测呋喃唑酮代谢物残留的方法。试验用呋喃唑酮代谢物的衍生物（CPAOZ）与牛血清白蛋白（BSA）的偶联物免疫小鼠,利用单克隆抗体技术制备杂交瘤细胞,用间接ELISA和间接竞争ELISA法对阳性克隆进行筛选。单克隆细胞株诱生腹水后,经纯化即为单克隆抗体,用于胶体金标记,制备呋喃唑酮代谢物胶体金免疫层析试纸条。融合后得到2株稳定分泌抗体的杂交瘤细胞株,其中4G3纯化后的抗体效价达到1:100万,对CPAOZ的50%抑制质量浓度（IC50）为1.7 μg/L,亲和常数Ka=1.6×109 L/mol。该抗体制备的胶体金试纸条的检测限为4 μg/L,与其他3种硝基呋喃代谢物的衍生物CPAHD、CPSEM和CPAMOZ均不存在交叉反应,对样品的检测与高效液相色谱结果一致。本研究制备了抗呋喃唑酮代谢物特异性单克隆抗体,并研制了以单抗为基础的胶体金免疫层析试纸条,能够实现呋喃唑酮代谢物残留的快速、灵敏的检测。     

免疫磁珠法检测食品中的沙门菌及分离菌株的耐药性

为检测沙门菌在本市食品中的污染和耐药情况,采集各类食品样品303件,经增菌后通过特异的免疫磁珠（IMS）吸附并接种XLD平板分离沙门菌.分离的菌株按年度分成2组,分别以改良K-B法测试对28种抗生素的耐药性.在303件样品中检出87件阳性,总阳性率28.71%.分离到的112株沙门菌以德比、肠炎血清型占优势.肉类制品的阳性率40.20%（82/204）明显高于其它食品,共分离出107株沙门菌（107/112,95.54%）.菌株耐药率在2年中有显著改变的抗生素有环丙沙星、复方新诺明、妥布霉素、二甲胺四环素、氯霉素和链霉素.耐10种以上抗生素的多重耐药株有12株（12/112,10.71%）,有4株头孢哌酮耐药株.IMS用于食品中沙门菌的分离效果较好.结果显示耐环丙沙星和多重耐药菌株的增多说明加强食源性沙门菌耐药监测的重要性。     

Improved Sample Preparation for Real-Time PCR Detection of Listeria monocytogenes in Hot-Smoked Salmon using Filtering and Immunomagnetic Separation Techniques

This work evaluated the application of filtration and immunomagnetic separation (IMS) as sample pretreatments for use in combination with real-time polymerase chain reaction (PCR) to detect and quantify Listeria monocytogenes in hot-smoked salmon. Salmon was artificially inoculated with L. monocytogenes at levels ranging from 8 × 10⁰ to 8 × 10⁵ cfu/g of sample, and homogenates obtained from these samples were filtered to recover bacterial cells without a pre-enrichment step. High recovery of bacterial cells was achieved using standard coffee filters. IMS significantly reduced the co-extraction of PCR inhibitors present in the samples to increase the assay sensitivity with regression line parameters applicable for quantification. The limit of detection and quantification were equal to 2 × 10¹–4 × 10¹ and 2 × 10² cfu/g of sample, respectively. The entire detection procedure could be completed within 3.5 h. This study demonstrated that coupling filtration and IMS with real-time PCR has contributed to improve the sensitivity of L. monocytogenes detection from hot-smoked salmon.     

纳米酶侧流免疫层析法快速检测食品中肠炎沙门氏菌

目的 基于氧化铈修饰的金纳米棒(CeO2 modified Au nanorod, AuNR@CeO2)纳米酶构建纳米酶侧流免疫层析法(lateral flow immunoassay, LFIA), 并用以检测食品中肠炎沙门氏菌。方法 采用模板法制备AuNR@CeO2纳米酶, 对纳米酶的酶促活性进行考察。将AuNR@CeO2标记抗体作为信号探针进一步构建试纸条, 优化其关键参数, 并利用AuNR@CeO2纳米酶的酶促活性, 催化放大试纸条的比色信号, 最后将其用于奶粉中肠炎沙门氏菌的检测。结果 成功制备了AuNR@CeO2纳米酶, 在最优条件 下(即：2% BSA+0.05% Tween-20的样品垫缓冲体系、0.8 mg/mL的T线抗体质量浓度和4 μL的探针使用量), 该试纸条可以实现目标菌的特异性检测, 检出测限 低至103 CFU/mL, 信号放大后灵敏度提高了10倍, 在人工污染奶粉样品中也表现出良好的检测效果 检出限低至103 CFU/mL。结论 本研究所制备的试纸条无需复杂仪器和专业人员即可实现目标物的检测, 且具有易操作、便携、快速的特点, 通过更换抗体类型便可用于各类食品有害物质的检测。     

Immunomagnetic reduction assay on chloramphenicol extracted from shrimp

The application of the assay methodology, called immunomagnetic reduction, using bio-functionalized magnetic nanoparticles as labeling markers for chloramphenicol was investigated. The reduction in the alternative-current (ac) magnetic susceptibility χ_ac of magnetic nanoparticles caused by the association between magnetic nanoparticles and chloramphenicol was detected as a function of the concentration of chloramphenicol. In this study, the characterizations used to detect chloramphenicol, such as low-detection limit and interference, were also conducted. Furthermore, the extracting processes for chloramphenicol from shrimp were explored. Thus, the platform for detecting chloramphenicol residue in shrimp via immunomagnetic reduction was demonstrated. Such platform showed features of a 0.1-ppb low-detection limit, low interference from other kinds of antibiotics, and easy operation.     

Optimization and evaluation of a modified enrichment procedure combined with immunomagnetic separation for detection of E. coli O157:H7 from artificially contaminated alfalfa sprouts

Escherichia coli O157:H7 has been linked to foodborne disease outbreaks with alfalfa sprouts. Detection of the organism in sprouts by standard cultural methods can be difficult due to the high background microflora. The objective of this study was to develop and optimize an enrichment protocol with and without post-enrichment immunomagnetic separation (IMS) for the rapid detection by real-time PCR (RTiPCR) and cultural recovery of E. coli O157:H7 from artificially contaminated alfalfa sprouts. Initially we found that the FDA BAM procedure, enriching samples in modified buffered peptone water with pyruvate and at 37 °C for 5 h, followed by the addition of acriflavin, cefsulodin and vancomycin (mBPWp + ACV) and static incubation at 42 °C gave poor results for both PCR detection and isolation for alfalfa sprouts artificially contaminated at 0.2 cfu/g. The addition of post-enrichment IMS improved detection but not isolation. This procedure was modified and optimized by changing to mBPWp with cefsulodin and vancomycin at 42 °C and shaking for 24 h with and without IMS prior to PCR detection and cultural isolation. Using the resulting protocol we were able to detect E. coli O157:H7 in 100% of samples of alfalfa sprouts contaminated at 0.2 cfu/g. This was validated for five strains of E. coli O157:H7. Isolation was 84% without added post-enrichment IMS and 100% with IMS. The optimized procedure was effective for detection and isolation of E. coli O157:H7 from this difficult food matrix.     

Identification of tuna species by a real-time polymerase chain reaction technique

Tuna are highly priced fishes that are often used in processed products. For effective fishery management and protection of consumers’ rights, it is important to develop a molecular method to identify the species of the tuna products. In this study we have developed a molecular method based on real-time polymerase chain reaction (real-time PCR) technology for the rapid identification of four tuna species. Four species-specific TaqMan probes were designed to identify bigeye tuna (Thunnus obesus), Pacific bluefin tuna (Thunnus orientalis), southern bluefin tuna (Thunnus maccoyii), and yellowfin tuna (Thunnus albacares). A SYBR green system was also designed to enhance the authentication of T. obesus. Both systems can distinguish target species from others in an efficient and high-throughput manner and can be applied to species identification of tuna products.     

SENSITIVE AND RAPID DETECTION OF ESCHERICHIA COLI O157:H7 IN GROUND BEEF BY NESTED PCR INCORPORATING IMMUNOMAGNETIC SEPARATION

A protocol for detection of low numbers of E. coli O157:H7 in ground beef by nested PCR incorporating immunomagnetic separation (IMS) was developed. The protocol enabled detection of 24 colony-forming-units (CFU) in 10 g of seeded ground beef without enrichment cultivation. Differential centrifugation was used for maximally recovering the target CFU. Partial digestion of the resulting cell pellet with proteinase K at 37°C was used for the removal of beef tissue, which was required for the proper function of IMS. Within the range of 24 to 2400 CFU/10 g, a log linear relationship between the numbers of inoculated CFU and the integrated intensity of the nested PCR products was obtained with both shiga-like toxin (SLT) 1 and 2 primer pairs.     

免疫磁珠分离技术在病原微生物检测中的应用

本文综述了免疫磁珠分离技术的基本原理、主要影响因素及其在病原微生物检测领域中的应用,重点介绍了该技术与传统的分离培养技术、PCR技术、免疫学技术联合使用后,可以更有效地分离各种标本中的病原体,提高实验室对致病微生物的检出率,缩短检测时间,为病原体检测提供了一种新的技术路线.     

复合凝聚法包埋功能性食品组分的研究进展

复合凝聚法是一种新兴的包埋技术,食品领域研究者对该技术日益关注。本文深入讨论了影响复合凝聚的 环境因素;以功能性油脂、精油、脂溶性维生素、脂溶性抗氧化物为代表组分,归纳总结了复合凝聚法包埋脂溶性 活性组分的研究进展;以益生菌、酶、水溶性维生素、甜味剂、苦味肽等为例,详细介绍了复合凝聚法包埋亲水性 活性组分的研究进展。     

免疫磁珠技术研究进展

该文介绍免疫磁珠结构特点、性质、及其在免疫检测、细胞分离、生物大分子纯化及分子生物学等方面应用,并概述免疫磁珠技术基本原理及其在黄曲霉毒素等检测中应用.