Study on the Production of Pentachloronitrobenzene Monoclonal Antibody and Its ELISA Kit for Rapid Detection

[Objectives]This study was conducted to develop an enzyme-linked immunoassay kit that can detect the residual amount of pentachloronitrobenzene in Penaeus vannamei.[Methods]This study was conducted to develop an enzyme-linked immunoassay kit that can detect the residual amount of pentachloronitrobenzene in P.vannamei.[Results]The standard curve range of the kit was 0-8.1μg/L;the detection limit for P.vannamei was 0.912μg/kg;the recovery was 80.6%-103.5%;and the relative standard deviation range within batches was 5.3%-10.1%,and the relative standard deviation range between batches was 6.7%-8.1%.The specificity of the pentachloronitrobenzene monoclonal antibody was relatively good,and the cross-reaction rates with pentachlorophenol,hexachlorobenzene,tetrachlorophthalide,and chlorothalonil were low,all of which did not exceed 30%.The ELISA kit could be stored at 4℃for 12 months,showing good stability.[Conclusions]The detection kit has low cost,short time and small deviation,and is an ideal preliminary screening method.

Determnation of ochratoxin A in grain by monoclonal antibody－based enzyme－linked immunosorbent assay

The simple rapid and sensitive enzyme-linked immunosorbent assay (ELISA) methods, di-rect and indirect ELISA, for quantitation of ochratoxin A in cereal had been developed by theutilization of monoclonal antibody on immunomicroplate. Direct FLIAS was found to be less timeconsuming than indirect ELISA. For direct FLISA, recovery of 1 -500 ppb OA added to wheat was78.9-100.0% and rice was 88.9- 120.0%. For indirect EI.IAS, recovery of 1-500 ppb OA addedto wheat was 79.0- 110.0% and rice was 82.0 120.0%. The minimal detection level for OA was Ippb. Analyses of 31 samples that caused humanintoxicant for OA showed that the ELISA resultsagreed wtll with those obtained by thin-layer chromatogrdphy.

Expression and identification of recombinant soluble single-chain variable fragment of monoclonal antibody MC3

AIM: To generate soluble single chain variable fragments (ScFv) of monoclonal antibody MC3 recognizing colorectal and gastric carcinomas.METHODS: mRNA was isolated from the hybridoma cell lineproducing MC3 and the DNAs encoding variable domains ofheavy and light chains(VH and VL) oftthe antibody wereamplified separately byRT-PCR and assembled into ScFvDNA with a linker DNAThe ScFv DNA was iigated into thephagemid vector pCANTAB5E and the ligated sample wastransformed into E. coil TG1. The transformed cells wereinfected with M13KO7 helper phage to yield recombinantphages. After two rounds of panning with gastric carcinomacell line AGS highly expressing MC3-binding antigen, thephage clones displaying ScFv fragments of the antibodywere selected by ELISA. 4 phage clones showing strongsignal in ELISA were used to infect E. coil HB2151 toexpress soluble ScFvs. The soluble ScFve were identified byDot blot and Western blot, and their antigen-binding activitywas assayed by ELISA. The VH and VL DNAs of the ScFvDNA derived from phage clone 19 were sequenced.RESULTS: The VH, VL and ScFv DNAs were about 340 bp,320 bp and 750 bp respectively. After two rounds of panningto the recombinant phages, 18 antigen-positive phageclones were selected from 30 preselected phage clones byELISA. All the soluble ScFvs derived from the 4 out of the 18antigen-positive phage clones were about Mr 32 000 andconcentrated in periplasmatic space under the given culturecondition. The soluble ScFvs could bind the antigen, andthey shared the same binding site with MC3. The sequencesof the VH and VL DNAs of the MC3 ScFv showed that thevariable antibody genes belonged to the IgG1 subgroup,κ-type.CONCLUSION: The soluble ScFv of MC3 is successfullyproduced, which not only provides a possible novel targetingvehicle for in vivo and in vitro study on associated cancers,but also offers the anuibody a stable genetic source.

Highly Sensitive and Specific Monoclonal Antibody-Based Serological Methods for Rice Ragged Stunt Virus Detection in Rice Plants and Rice Brown Planthopper Vectors

Rice ragged stunt virus（RRSV） is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein（CP） gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21（DE3） using the pMAL-C2 X expression vector. The recombinant protein was used as the immunogen to immunize BALB/c mice. A hybridoma cell line 8A12 secreting monoclonal antibody（MAb） against RRSV was obtained by fusing mouse myeloma cells（Sp 2/0） with spleen cells from the immunized BALB/c mice. Western blot analysis showed that the MAb 8A12 can specifically react with RRSV CP. Using the MAb, an antigen-coated-plate enzyme-linked immunosorbent assay（ACP-ELISA）, a dot enzyme-linked immunosorbent assay（dot-ELISA）, and immunocapture-RT-PCR（IC-RT-PCR） assay were developed to detect RRSV. The established ACP-ELISA, dot-blot ELISA and IC-RT-PCR methods could detect RRSV in infected rice tissue crude extracts with dilutions of 1：40 960, 1：1 280 and 1：655 360（w/v, g mL-1）, respectively. The ACP-ELISA and dot-blot ELISA methods could detect RRSV in infected insect vector crude extracts with dilutions of 1：12 800 and 1：1 600（an individual planthopper μL-1）, respectively. The field survey revealed that Rice ragged stunt disease occurs on rice in Hainan, Yunnan, Guangxi, Sichuan, Guizhou, Fujian, Hunan, Jiangxi and Zhejiang in China.

Characterization of Monoclonal Antibody to L-Homocysteic Acid and Its Immunohistochemistry in Rat Hippocampus

L-homocysteic acid (HCA) and other amino acids were conjugated to rat brain material (extracted rat brain protein) with glutaraldehyde to form HCA- and amino acids-brain material conjugates. The specificity of monoclonal antibody (McAb) was tested on serial dilution test and absorption test on enzyme-linked immunosorbent assay (ELISA) using these conjugates as antigens instead of amino acids-BSA (bovine serum albumin) conjugates used previously. The characterized McAb was applied for immunohistochemical staining using PAP (peroxidase antiperoxidase) technique in combination with silver enhancement of diamino-benzene (DAB) products. The results indicated that McAb to L-HCA reacted with L-HCA-brain material conjugates, but not with other amino acids-brain material conjugates so far tested. McAb absorbed with L-HCA-brain material abolished or decreased immunoreactivity of L-HCA-brain material with McAb. The antibody selectively stained subpopulation of cells and processes in the hippocampus fixed with glutaradehyde. Absorption of McAb with L-HCA-brain material abolished immunohistochemical staining. These results suggested that McAb was specific for L-HCA-brain materials and could be used for imunohistocytochemistry. This would provide a new tool for immunohistochemical visualization and localization of L-HCA in the nervous system.

人C-反应蛋白磁微粒化学发光酶免疫测定法的建立

人C-反应蛋白(C-reactive protein,CRP)是炎症以及各种相关疾病如病毒感染、心血管疾病等诊断、治疗和预后的临床检测指标。为了建立一种快速、准确的CRP定量免疫测定方法,将表达纯化的重组CRP作为抗原免疫小鼠,获得了5株稳定分泌抗体的单克隆抗体细胞株,采用双抗体夹心酶联免疫吸附测定法(double antibody sandwich enzyme-linked immunosorbent assay,DAS-ELISA)初步鉴定筛选的抗人CRP单克隆抗体,并分别选择mAb 9D6和mAb 9G4作为捕获抗体与检测抗体,建立用于人CRP检测的化学发光酶免疫测定法(chemiluminescence enzyme immunoassay,CLEIA),最后通过测定分析临床血清CRP样本,评价CLEIA的性能。结果显示,基于9D6/9G4-AP单克隆抗体对的CLEIA测定范围为0.1767~500μg/L(可扩展至100 mg/L);所建立的CLEIA与医院采用的免疫散射比浊法(R^(2):0.9496,P<0.0001)表现出良好的相关性,且Bland-Altman分析中96.36%(106/110)的点在95%一致性界限范围内显示两种检测方法具有较好的一致性。结果初步表明,建立的分析方法在临床诊断中具有较好的应用前景。

米酵菌酸单克隆抗体的制备与鉴定

目的建立鲜湿米粉中米酵菌酸(bongkrekic acid,BA)的免疫学快速检测方法,制备特异性识别BA的单克隆抗体并进行评价。方法利用碳二亚胺[1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride,EDC]法将BA半抗原与牛血清白蛋白(bovine serum albumin,BSA)和卵清蛋白(ovalbumin,OVA)载体偶联,分别合成BA免疫原(BA-BSA)和包被原(BA-OVA),用BA-BSA免疫Balb/C小鼠,取免疫效果好的小鼠脾脏与小鼠NS-1骨髓瘤细胞进行融合。采用间接竞争酶联免疫吸附法(indirect competitive enzyme-linked immunosorbent assay,icELISA)进行筛选,筛选出能分泌所需特异性抗体的杂交瘤细胞,利用有限稀释法进行亚克隆得到单株能稳定分泌所需抗体的细胞;采用体内诱生法制备腹水型单克隆抗体。利用正辛酸-饱和硫酸铵法纯化腹水型抗体,通过酶联免疫吸附法测定纯化后的抗体效价。结果成功合成了BA免疫原BA-BSA和BA包被原BA-OVA,筛选获得BA杂交瘤细胞株BA-3F1E9,单克隆抗体的效价为1×10^(5)。结论本研究建立了制备高特异性BA单克隆抗体的方法,为开发鲜湿米粉中BA快速检测试剂盒提供了理论依据。

半抗原直接包被的四环素酶联免疫吸附分析法的建立

为建立更优的四环素(tetracycline,TC)酶联免疫吸附分析法(enzyme-linked immunosorbent assay,ELISA),将TC与蛋白质偶联制备人工完全抗原免疫BALB/c小鼠,获得抗TC的单克隆抗体(monoclonal antibody,MAb)。采用酸性高锰酸钾羧化酶标板,将TC直接包被在酶标板上,并对ELISA反应体系条件进行优化,构建一种半抗原直接包被的TC ELISA检测方法。所制备的MAb特异性良好,交叉反应率低。所构建的检测方法最低检测限IC_(10)值为0.306 ng/mL,半数抑制率IC_(50)值为9.26 ng/mL,牛奶和水中加标回收率分别为96.46%~101.89%、96.84%~102.50%。与人工完全抗原包被的检测方法相比(IC_(10)值:0.624 ng/mL,IC_(50)值:28.24 ng/mL,牛奶和水中加标回收率分别为93.86%~105.12%、94.04%~105.56%),检测灵敏度有明显提高,并可用于实际样品中TC含量的检测,具备良好的应用前景。

Development of Monoclonal Antibody-based Enzyme-linked Immunosorbent Assay to the Estrogen Diethylstilbestrol

Diethylstilbestrol （DES） is a synthetic estrogen that has ever been used worldwide. Polyclonal antibodies （PAbs） were used in immunoassay for detection of DES residues in environmental and agricultural samples in previous paper. In this paper, an indirect competitive enzyme-linked immunosorbent assay （icELISA） was developed based on monoclonal antibody （MAb） for the determination of diethylstilbestrol. Mono-o-carboxypropyldiethylstilbestrol （DES-CP） and mono-o-carboxymethyldiethylstilbestrol （DES-CME） were synthesized to be haptens. DES-CP was coupled to bovine serum albumin （BSA） to be an immunogen in BALB/c female mouse for MAb production. The MAb was characterized for specificity and affinity to DES in icELISA. Under the optimum condition, the icELISA showed an ICs0 of 9.8 ng/mL, the limit of detection （IC20） of 2.3 ng/mL and a working range of 2-42 ng/mL. Hexestrol and dienestrol exhibited cross-reactivity values were 44% and 27%, respectively. Cross-reactivity of natural estrogen 17β-estradiol was less than 0.1%. The influences of some factors such as salt concentration, pH and organic solvent concentration on the assay were evaluated. The concentrations of DES in the fortified water samples determined by the assay were correlated well with the fortification levels. The results were conf＇m＇ned with analysis by HPLC.

Production and Characterization of Monoclonal Antibodies to Bluetongue Virus

In the present study,a total of 24 MAbs were produced against bluetongue virus (BTV) by polyethyleneglycol (PEG) mediated fusion method using sensitized lymphocytes and myeloma cells. All these clones were characterized for their reactivity to whole virus and recombinant BTV-VP7 protein,titres,isotypes and their reactivity with 24 BTV-serotype specific sera in cELISA. Out of 24 clones,a majority of them (n = 18) belong to various IgG subclasses and the remaining (n = 6) to the IgM class. A panel of eight clones reactive to both whole BTV and purified rVP7 protein were identified based on their reactivity in iELISA. For competitive ELISA,the clone designated as 4A10 showed better inhibition to hyperimmune serum of BTV serotype 23. However,this clone showed a variable percent of inhibition ranging from16.6% with BTV 12 serotype to 78.9% with BTV16 serotype using 24 serotype specific sera of BTV originating from guinea pig at their lowest dilutions. From the available panel of clones,only 4A10 was found to have a possible diagnostic application.

CYTOTOXICITY OF INDIRECT IMMUNOTOXIN MEDIATED BY ANTI-GASTRIC CANCER MONOCLONAL ANTIBODIES ON TUMOR CELLS

In the present study, an indirect assay was employed to investigate 5 anti-gastric cancer monoclonal antibodies for their cytotoxic potential as ricin A chain-containing immunotoxins. The tumor cell, were treated with dilutions of tested antibody followed by ricin A chain coupled to goat anti-mouse immunoglobulin. The cytotoxic effect was determined with tetrazolium colorimetric assay. The results showed that among the 5 antibodies chosen, MGb2 and MG7 could be well used for preparation of effective A chain immunotoxins.

基于免疫磁珠净化间接竞争酶联免疫吸附试验检测氟喹诺酮类药物

本研究旨在建立一种基于免疫磁珠进行分离、富集和净化前处理,检测鸡肉、鸡肝和鱼肉中氟喹诺酮类药物残留的间接竞争酶免疫吸附试验(indirect competitive enzyme-linked immunosorbent assay,icELISA)的研究方法。通过对合成免疫磁珠及免疫磁珠净化过程中单克隆抗体添加量、偶联时间、缓冲液pH、抗原添加量、抗原捕获时间、温度及包被条件等进行优化,初步建立了基于免疫磁珠净化的icELISA检测方法。结果显示:1)在1 mg的磁珠中,沙拉沙星(sarafloxacin,SAR)单克隆抗体最佳偶联量为15μg,偶联时间60 min,pH为4.4;2)最佳抗原添加量为1 ng·mL^(-1),捕获时间40 min,缓冲液为0.01 mol·L^(-1)PBS,IC50为0.73 ng·mL^(-1),线性范围为1.0~3.2 ng·mL^(-1);3)氟喹诺酮类药物在鸡肉、鸡肝、鱼肉的检测限均不超过1.33、2.17、2.31μg·kg^(-1),回收率为76.83%~98.70%,批内变异系数批间变异系数均不超过15%,经验证,鸡肉样本检测结果与高效液相色谱法(HPLC)结果一致。结果表明,与传统仪器检测方法相比,该方法提高了检测氟喹诺酮类药物的简便性、选择性以及检测效率,为氟喹诺酮类药物的残留检测提供了新思路。

水果及环境水样中苯醚甲环唑的高灵敏免疫分析方法研究

采用辣根过氧化物酶(HRP)催化氧化四甲基联苯胺(TMB)显色为信号输出系统,结合间接竞争反应模式建立了水果及环境水样中苯醚甲环唑的间接竞争酶联免疫分析方法(ic ELISA)。基于高特异性单克隆抗体,通过逐步优化策略,确定最佳免疫分析条件为:包被原与抗体质量浓度组合为62.5 ng/mL和0.318μg/mL,一抗竞争反应缓冲溶液为含0.05%Tween-20的0.01 mol/L磷酸盐缓冲液(PBST,pH 7.4),一抗竞争反应时间为20 min,酶标二抗稀释液为0.01 mol/L磷酸盐缓冲液(PBS,pH 7.4),酶标二抗反应时间为30 min。在该条件下,苯醚甲环唑的线性检测范围(IC_(20)~IC_(80))为0.49~3.90 ng/mL,半数抑制浓度(IC_(50))为1.38 ng/mL,检出限(LOD)为0.33 ng/mL。在柑橘、葡萄、香蕉、草莓田水、湖水和河水样品中的平均加标回收率为72.3%~132%,相对标准偏差(RSD)不大于13%,对10种结构和功能类似物的交叉反应率(CR)均小于0.2%。该方法准确可靠,可用于水果及环境水样中苯醚甲环唑的快速筛查和残留检测。

基于磁性纳米颗粒伏马菌素B双探针竞争ELISA检测方法的建立

建立一种基于磁性纳米颗粒能同时检测样品中伏马菌素B_(1)(fumonisin B_(1),FB_(1))、FB_(2)和FB_(3)总量的双探针竞争酶联免疫吸附实验(enzyme linked immunosorbent assay,ELISA)检测方法。采用通过活化酯法制备磁性纳米颗粒-FB_(1)捕获探针,利用改良过碘酸钠法合成McAb-HRP探针,对检测步骤进行优化,确定最佳反应条件。所建立检测方法对FB_(1)和FBs的检测范围分别为0.07~1.98 ng/mL和0.10~9.86 ng/mL。在玉米样品中加标回收率范围为86.2%~105.1%。所建立方法检测结果与液相色谱-串联质谱检测结果的相关系数(R^(2))为0.9966。双探针竞争ELISA检测法检测速度快、准确性高、重复性好,为玉米中伏FBs的快速筛选提供了新方法。

雌二醇单克隆抗体制备及胶体金侧流层析免疫分析方法的建立

目的探讨雌二醇(17β-estradiol,E2)的3号位和17号位引入活性基团制备的半抗原对抗体灵敏度的影响,选用灵敏度较高的抗体建立一种牛奶中E2胶体金侧流层析免疫分析方法(colloidalgold-basedlateral flow immunoassay,CG-LFA)。方法从E2的3号位羟基和17号位羟基引入活性基团分别制备半抗原H1a和H2,偶联载体蛋白制备完全抗原,经过动物免疫和细胞融合筛选,制备单克隆抗体(monoclonal antibodies,mAbs),采用间接竞争酶联免疫吸附实验(indirect competitive enzyme-linked immunosorbent assay,icELISA)对mAbs性能进行评估,筛选出灵敏度最高的mAb,最后采用静电吸附法将胶体金标记抗体为探针,构建牛奶中E2的CG-LFA。结果制备了H1a-7B7、H1a-7B12、H1a-9C7、H1a-10E7、H2-2E2、H2-3C10、H2-4A10和H2-6D28种mAbs,经过icELISA评估,其半数抑制浓度(half maximal inhibitory concentration,IC50)分别为0.116、0.207、0.072、0.370、0.442、6.170、0.415和4.411 ng/mL,最终选取H1a-9C7,构建牛奶中E2的LFA,消线(cut-off)值为6.00ng/mL,与苯甲酸雌二醇和雌三醇的交叉反应率分别为101.31%和2.43%,在真实样本加标回收实验中,检测结果与液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry,LC-MS/MS)结果一致。结论E2的3号位引入活性基团设计合成的半抗原所制备的E2抗体灵敏度,比17号位引入活性基团制备的抗体灵敏度高,并且建立的LFA准确度良好,为牛奶中E2快速检测提供了一定的技术手段。

草甘膦单克隆抗体的制备及酶联免疫分析方法的建立

目的制备出草甘膦(glyphosate,GLY)单克隆抗体,建立间接竞争酶联免疫吸附法(enzyme linked immunosorbent assay,ELISA)快速检测茶叶中GLY的方法。方法首先合成GLY完全抗原(包被原和免疫原),通过免疫小鼠成功制备出GLY单克隆抗体。根据ELISA的检测流程,采用棋盘法确定最佳包被抗原和抗体的稀释倍数,确定最佳包被的温度和时间,并确定最佳加入一抗、二抗后反应时间,建立检测方法并对其性能进行评价。结果GLY包被抗原和抗体的稀释倍数为1:2000,包被温度为37℃、包被时间为90 min,加入一抗、二抗后反应时间为60 min。该方法的线性方程为Y=-0.2353X+0.6539(r2=0.9871),半抑制浓度(50%inhibiting concentration,IC50)为4.508 ng/mL,检出限为1.18 ng/mL。变异系数均在10%以下,与异菌脲、多菌灵、三唑磷、甲基对硫磷、噻菌灵这5种标准品的交叉反应率均低于0.03%,在茶叶中加标回收率为90.86%~110.35%,且相对标准偏差均小于10%。结论该方法具有较高的灵敏度和特异性,可用于茶叶样本中GLY残留的快速检测。

PRODUCTION AND CHARACTERIZATION OF A MONOCLONAL ANTIBODY AGAINST TRICHOTHECENE MYCOTOXIN T-2

Trichothecene mycotoxin T-2 is a secondary metabolite of several Fusarium species, and is known as a natural contaminant of stored grain and other agricultural products. This compound is a potent inhibitor of protein synthesis and has been implicated as the causative agent of several mycotoxicoses. There is also a close relationship between T-2 toxin and esophageal carcinoma, Keshan, Kaschin-Beck diseases in China.

赭曲霉毒素A免疫学检测方法的研究

目的 建立敏感、特异和快速针对赭曲霉毒素A的酶联免疫吸附试验检测方法 ,研制具有我国自主知识产权的快速检测试剂盒。方法 利用B细胞杂交瘤技术 ,建立能够分泌抗赭曲霉毒素A单克隆抗体的杂交瘤细胞株 ,并获得抗赭曲霉毒素A单克隆抗体。结果 建立赭曲霉毒素A的间接竞争抑制性酶联免疫吸附试验测定方法(ELISA)。该方法的最低检出浓度为 0 5ng/ml,线性范围 2～ 5 0 0ng/ml,线性方程Y =0 2 72X +1 0 7(r =0 9978)。方法的加标回收率为 79 0 %～ 119 7%。利用该方法对北京市售的大米、小麦样品进行检测。结果表明 ,小麦样品的污染率为 6 0 71% ,最大值为 8 2 6 μg/kg ;大米样品的污染率为 17 86 % ,最大值为 3 4 4 μg/kg。结论 该方法简单、快速、灵敏 。

吡虫啉的酶联免疫吸附分析方法研究

通过碳二亚胺法将吡虫啉交联于牛血清蛋白(BSA)作为免疫抗原,混合酸酐法将吡虫啉交联于卵清蛋白(OVA)作为包被抗原,免疫Balb/c小鼠,采用B细胞杂交瘤技术,经免疫、融合、筛选、克隆,得到抗吡虫啉单克隆抗体,抗体亚类为IgG1,制备的单克隆抗体效价达1×107,确定了吡虫啉酶联免疫吸附分析方法(ELISA)的最佳工作条件,建立了定量测定吡虫啉的间接竞争ELISA方法。本方法的IC50为(15.12±1.28)μg/L,检出限为(1.76±0.02)μg/L。与其它吡虫啉结构类似物无交叉反应。批内相对标准偏差为4.5%;批间相对标准偏差5.1%,饮用水、重庆理工大学地下水和重庆市花溪河地表水平均添加回收率分别为102%,97%和85%。本研究建立了一种快速检测环境水中吡虫啉残留的方法。

中药致肾毒性成分马兜铃酸A单抗制备及酶联免疫分析方法的建立

采用活化酯法,将马兜铃酸A分别与牛血清蛋白(BSA)和卵清蛋白(OVA)偶联,得到免疫抗原马兜铃酸A-BSA和包被抗原马兜铃酸A-OVA。利用马兜铃酸A-BSA免疫Balb/c小鼠,制得鼠单克隆抗体1A11,单抗效价为2×104;单抗为IgG1类,轻链为κ型;与其结构类似物马兜铃酸B、C和D的交叉反应率分别为2.8%,3.5%和31.2%。基于抗马兜铃酸A单克隆抗体的间接竞争酶联免疫分析方法(icELISA)的IC50为1.9μg/L,检测范围为0.5～7.5μg/L。icELISA添加回收率为86%～97%,相对标准偏差在5.2%～11.1%之间。利用所建立的icELISA测定了6个中药材和5个中成药中马兜铃酸A的含量,并用高效液相色谱法(HPLC)进行了验证,其中关木通、广防己、天仙藤、马兜铃和青木香中均检测出马兜铃酸A,而川木通和5个中成药中未检测到马兜铃酸A。结果表明:本方法可用于中药中马兜铃酸A的快速检测。