链霉素人工抗原及多克隆抗体的制备与鉴定

通过研究链霉素(SM)人工抗原的合成和多克隆抗体的制备,建立链霉素残留的免疫分析方法。以氧-缩甲基羟胺肟化链霉素的醛基,引入羧基,再用碳二亚胺法将半抗原与蛋白质载体连接,合成免疫原SM-cBSA。用戊二醛法合成包被原SM-OVA。用紫外扫描、SDS-PAGE分析偶联情况,计算得链霉素与cBSA、OVA的分子偶联比分别为7.6:1与17.7:1。经动物免疫获得效价为1:40000的链霉素多克隆抗体,采用间接竞争ELISA测定IC50为3.32ng/mL,与双氢链霉素的交叉反应率为105.21%,与同类的其他药物均无交叉反应。     

氟喹诺酮药物格林沙星抗体制备及其icELISA方法建立

目的:制备格林沙星多克隆抗体并建立间接竞争酶联免疫吸附分析方法(icELISA)。方法:采用碳二亚胺法将格林沙星偶联于牛血清白蛋白(BSA)作为免疫原,免疫新西兰大白兔获多克隆抗体;采用活泼脂法分别将格林沙星、克林沙星、加替沙星、培氟沙星和沙拉沙星偶联于卵清白蛋白(OVA),制备5种包被抗原并做性能比较;建立icELISA方法并对其灵敏度和特异性进行评价。结果:成功制备了免疫原和包被抗原及抗体,抗体效价最高达64 000倍。以克林沙星-OVA作异源包被,建立的icELISA方法灵敏度最高,半抑制药物浓度(IC50)为9.14 ng/mL,检测限(IC10)为0.9 ng/mL,检测范围(IC20~IC80)为2.3~36.4 ng/mL,与其他喹诺酮类药物无明显交叉反应。结论:首次制备出格林沙星抗体并建立间接竞争酶联免疫吸附检测方法,该法灵敏度高、特异性强,为分析生物样品中格林沙星含量的测定提供了1种新的方法。     

重金属镉特异性抗体的制备及icELISA检测方法的建立

为检测食品中的重金属镉残留问题,本研究建立了基于重金属镉抗体的酶联免疫分析方法。利用异硫氰酸苄基乙二胺四乙酸(Isothiocyanobenzyl-EDTA,ITCBE)螯合Cd~(2+)并偶联牛血清白蛋白(BSA)和卵清白蛋白(OVA),合成了针对Cd~(2+)的免疫原Cd-ITCBE-BSA和包被原Cd-ITCBE-OVA,通过紫外扫描鉴定说明偶联成功;以Cd-ITCBE-BSA免疫Balb/c小鼠,制备出Cd~(2+)抗血清并对其免疫学特性进行鉴定,进一步说明了抗原合成成功,在此基础上进行了条件优化并建立了针对镉的icELISA检测方法。方法的检测限(IC10)为0.18 ng/mL,IC50为1.15 ng/mL,线性检测范围(IC20～IC80)为0.24～5.54 ng/mL。除了与Hg~(2+)有2.16%的交叉反应率,该方法对Pb~(2+)、Fe~(3+)、Cu~(2+)和Cr3+交叉反应率均小于0.3%,板内变异系数和板间变异系数都低于10%。此抗体特异性强灵敏度高,建立的icELISA方法可应用于食品中重金属镉的快速检测。     

米诺环素完全抗原的制备与表征

研究制备能有效用于米诺环素(MNC)残留检测的完全抗原。采用戊二醛合成法和重氮化合成法,将米诺环素与牛血清白蛋白(BSA)偶联,分别制备MNC 完全抗原MNC-BSA。经红外和紫外光谱扫描结果表明：两种物质已经偶联,两种完全抗原的平均偶联比分别为9.9 和5.9。采用戊二醛法合成的完全抗原免疫兔,检测抗血清效价为1:16000,表明合成的完全抗原可以作为免疫原用于制备抗体及检测时的包被原进行ELISA 检测。     

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(bongkrekicacid,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(bovineserumalbumin, 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-OV...     

卡巴氧的代谢物喹喔啉-2-羧酸人工抗原的合成及其多克隆抗体的制备

实验采用碳二亚胺法将卡巴氧代谢物喹喔啉-2-羧酸（QCA）与牛血清白蛋白（BSA）偶联,采用用混合酸酐法将其与卵清白蛋白（OVA）偶联,分别将其作为免疫原（QCA-BSA）和包被原（QCA-OVA）进行抗血清的制备及ELISA实验。经过多次动物免疫及EILSA实验,结果表明,获得了高效价的特异性抗体。     

食品中苏丹红I酶联免疫检测方法的建立及酶学性质研究

为了检测食品中非法添加物苏丹红,采用重氮化法合成了2种苏丹红Ⅰ的衍生物,通过液相色谱-质谱(LC/MS)鉴定后,分别将两种衍生物与载体蛋白牛血清白蛋白(BSA)以及卵清蛋白(OVA)偶联制备完全抗原。紫外光谱表征结果证明衍生成功。将制备的BSA络合物做为免疫原免疫兔子,制备了多克隆抗体。采用方阵法确定了抗体和包被抗原的稀释比例。对影响酶免疫检测方法(ELISA)的因素包括包被液,封闭液,样品稀释液,抗体稀释液,反应时间等进行了优化。在最适反应条件下,以苏丹红质量浓度为横坐标,吸光度值为纵坐标建立了抑制曲线,线性范围为0.3~23.4 ng/mL,苏丹红Ⅰ的半数抑制率(IC50)为3.0 ng/mL,检测限(LOD)为0.1 ng/mL。交叉反应测试表明,与对位红交叉反应率为140%;与苏丹红Ⅱ、苏丹红Ⅲ、苏丹红G的交叉反应率分别为1.1%,6.85%,6.5%;与苏丹红Ⅳ的交叉反应率<0.1%。以辣椒粉为样本,在5 ng/g和20 ng/g添加水平下得到回收率分别为90.4%和96.0%,变异系数分别为1.8%和4.9%。     

孔雀石绿多克隆抗体的制备与筛选

设计并成功合成了三种孔雀石绿半抗原,所有半抗原均采用活化酯法分别与血匙兰蛋白(KLH)偶联制备成免疫抗原,与卵清蛋白(OVA)偶联制备成包被抗原。利用所制备的三种免疫原免疫新西兰大耳白兔都获得了高效价的抗孔雀石绿抗体,并将每一种抗体都与三种包被抗原进行组合配对,通过间接竞争酶联免疫吸附检测(ELISA)方法筛选出最佳的抗体-包被抗原组合,筛选出的抗体采用Sepharose FF-Protein A亲和层析柱纯化,采用间接ELISA法测定效价及鉴定特异性。经测定筛选出的抗体效价达到1:12000,IC50值为0.65 ng/mL,交叉反应表明该抗体有较好的特异性,与结构类似物结晶紫的交叉反应率为18.73%,与隐性孔雀石绿及隐性结晶紫的交叉反应率低于10%。本研究为建立快速检测食品中孔雀石绿残留的免疫分析方法奠定了基础。     

格列本脲人工抗原的合成与鉴定

目的：合成格列本脲人工抗原。方法：采用对氨基苯甲酸法制备半抗原,将半抗原分别与牛血清白蛋白(BSA)和卵清蛋白(OVA)通过碳二亚胺法偶联制备免疫原(Gli-BSA)和包被原(Gli-OVA),利用紫外扫描进行抗原的化学鉴定,通过免疫原免疫Balb/c小鼠,间接酶联免疫吸附法测定抗血清进行生物鉴定。结果：制备了Gli-BSA、Gli-OVA的人工抗原,经紫外光谱扫描,偶联比分别为4:1和17.7:1。免疫小鼠后获得抗血清的效价均达到32000以上,半抑制质量浓度为10μg/mL。结论：成功合成了格列本脲人工抗原,并获得了格列本脲抗体,为格列本脲的免疫学检测方法进一步研究提供了实验基础。     

氯霉素全抗原的合成与鉴定

目的：为获得较高偶联率氯霉素全抗原,探索和优化碳二亚胺法(EDC)合成氯霉素(CAP)与牛血清白蛋白(BSA)全抗原合成条件。方法：采用单因素设计,优化影响合成的主要因素：蛋白浓度、CAP 与BSA 的摩尔比例、反应体系pH 值,通过紫外法和三硝基苯磺酸(TNBS)法测定合成后的偶联率。 结果：EDC 法合成氯霉素抗原较优条件为BSA 浓度15mg/ml、CAP:BSA=70:1、pH7.4,可得到偶联率为15 左右的氯霉素全抗原。结论：EDC法可用于制备较高偶联率的氯霉素全抗原,以用来进行抗体制备。     

A double antibody sandwich enzyme-linked immunosorbent assay for the detection of Salmonella using biotinylated monoclonal antibodies

A double antibody sandwich enzyme-linked immunosorbent assay (ELISA) was developed using monoclonal antibodies (MAbs) as a rapid, economical alternative to culture isolation procedures for detection of Salmonella. Four MAbs previously shown to react with Salmonella strains representing 18 different serogroups were evaluated as capture antibodies and, after biotinylation, as detection antibodies. One MAb (M183) was selected for use in the ELISA to capture and detect Salmonella antigens. The detection limit of the ELISA was evaluated using Salmonella enterica subspecies enterica serovar Typhimurium and various selective and nonselective Salmonella enrichment media. The highest detection limit (ca. 10(4) CFU/ml) was achieved using an enrichment broth containing brain heart infusion, yeast extract, sodium hydrogen selenite, and sodium cholate (BYSC) after preenrichment in buffered peptone water. The ELISA detected all Salmonella serovars tested, which included representative serovars of serogroups B, C, D, and E and gave negative results for all non-Salmonella species tested. Samples (106) from various sources, including fecal samples from humans and pigeons, chicken carcass rinses, chicken parts, feed, and the environment, were used to evaluate the performance of the ELISA. The ELISA had a specificity and sensitivity of 100 and 91%, respectively, and a kappa value of 0.93 relative to the culture methods. Such an ELISA has the potential to be used in the implementation of the pathogen reduction and hazard analysis critical control point systems as well as in clinical laboratories.     

红曲中桔霉素的免疫检测(Ⅰ)抗原与抗体的制备

桔霉素抗原与抗体的制备是其免疫检测研究的第1步。桔霉素与BSA／OV的反应起始摩尔比为6：1，得到桔霉素与BSA的连接物及桔霉素与OV的连接物摩尔比分别为3．12：1和2．87：1。以桔霉素与OV的连接物为免疫抗原，免疫BALB／c小白鼠，分析了抗体的产生进程、灵敏度与效价。注射抗原后的第45天开始有明显的抗体产生，第90天达到高峰，然后开始下降，抗体的ELISA效价达到1：2000，和游离半抗原(桔霉素)的竞争ELISA表明，抗体有很好的灵敏度。     

RAC-OVA抗原和抗RAC单克隆抗体的筛选

在进行酶联免疫反应实验操作过程中,为了保证材料质量及使用的延续性,在使用前分别对两对抗原抗体进行了筛选和评价.主要是从抗体灵敏度的测定、抗体特异性的测定和抗体效价的测定这三个方面采选择灵敏度好、特异性强和效价高的一对抗原抗体.其中抗体灵敏度的测定中,单位1(江南大学)的抗体IC50的平均值为3.22 μg/L,灵敏度较...     

孔雀石绿人工抗原的合成及多克隆抗体的制备

通过研究孔雀石绿(MG)抗原的合成和多克隆抗体的制备,探索研究食品中孔雀石绿残留的检测方法。本实验先合成含有羧基的孔雀石绿半抗原(CMG),并用液-质联用法进行分析鉴定。半抗原经重氮化法处理后分别偶联两种载体蛋白BSA和OVA,并通过紫外分光光度法进行鉴定。与CMG标准品和两种载体蛋白的紫外吸收光谱相比,偶联物的吸收峰发生了明显的偏移,计算得免疫原的偶联比为10.6:1,说明偶联成功。通过免疫制备多克隆抗体,并通过间接ELISA法对CMG抗血清的效价进行检测,并进一步检测抗体的特异性,两只兔子的IC50值分别为8.1ng/mL和4.6ng/mL。     

乳粉中阪崎肠杆菌污染检测试剂盒的研制

目的：以乳粉中污染的阪崎肠杆菌（Enterobacter sakazakii）为检测目标,开发一种能快速检测其污染的试剂盒。方法：以两株阪崎肠杆菌单克隆抗体分别为包被抗体和检测抗体,建立双抗体夹心酶联免疫吸附实验方法,优化各个反应条件,制成在2 h内能发生显色反应的检测试剂盒。结果：包被抗体的最佳工作质量浓度为10 μg/mL,检测抗体的最佳稀释倍数为1∶5 000。试剂盒的检测限为104 CFU/mL,在104～108 CFU/mL范围内OD450 nm值与阪崎肠杆菌浓度的常用对数值呈线性关系。特异性实验中,试剂盒可检出3 株阪崎肠杆菌标准菌株,对其他9 株食品中常见致病菌的检测均呈阴性。模拟带菌实验中,初始菌浓度为1 CFU/mL的模拟样品经过8 h前增菌后,通过该试剂盒便可检出。该试剂盒的批内、批间变异系数均小于6%,至少可在室温保存6 个月。结论：该双抗体夹心试剂盒具有灵敏度高、特异性好、精密度高、稳定性强等优点,可应用于乳粉中阪崎肠杆菌的快速检测。     

硅胶载体氯霉素免疫亲和柱的制备

以硅胶为载体,通过硅烷偶联剂3-氨基丙基三乙氧基硅烷在其表面引入氨基,采用戊二醛法与氯霉素抗体进行偶联。该方法制备的免疫亲和柱对氯霉素抗体的偶联率达到72%,对氯霉素的最大吸附容量达到80ng/mL柱体积, 选择含70%甲醇的PBS为洗脱溶液。以牛奶为检测对象分别采用3种不同方法进行样品处理,利用免疫亲和柱实现对样品中痕量残留的氯霉素纯化富集并进行ELISA检测。     

Selective Immunodetection of Difloxacin in Animal Muscles and Sera: Role of Hapten Orientation

The influence of sarafloxacin (SAR) hapten orientation in immunogen on antibody specificity was examined. The spatial orientation of SAR linked through its carboxyl group to the carrier resulted to SAR-selective response (Anal Methods 2016, 8:5843–5850). To provide opposite orientation of SAR in immunogen, it was linked by its secondary amine to (1) succinic anhydride-modified BSA using carbodiimide-mediated conjugation and to (2) unmodified BSA using formaldehyde condensation method. Two versions of indirect competitive enzyme-linked immunosorbent assays (ELISA) based on generated antibodies were developed. A panel of homo- and heterologous conjugates was examined as potential coating antigens. No cross-reactions were registered in ELISA-1 and ELISA-2 except for fluorophenyl-containing fluoroquinolones difloxacin (DIF), SAR, and tosufloxacin as 138, 100 and 25% and 175, 100 and 8%, respectively. Among the recognized analytes, only DIF is authorized in meat products, so the developed tests were selective for DIF determination in bovine and porcine muscles and sera samples. The values of half-maximal inhibition concentration (IC₅₀) for these assay versions were estimated to be 1.2 and 0.25 ng/ml. DIF detection limits (IC₁₀) were, respectively, 0.15 and 0.015 ng/ml that allowed measuring of MRL and ten times lower level of DIF in the animal muscles. The developed ELISAs were also suitable for DIF determination in animal sera in the concentration range 1000–1 ng/ml.     

RAG-OVA抗原和抗RAG单克隆抗体的筛选

在进行酶联免疫反应实验操作过程中,为了保证材料质量强使用的延续性,在使用前分别对两对抗原抗体进行了筛选和评价。主要是从抗体灵敏度的测定、抗体特异性的测定和抗体效价的测定这三个方面来选择灵敏度好、特异性强和效价高的一对抗原抗体。其中抗体灵敏度的测定中,单位1（江南大学）的抗体IC50的平均值为3．22μg／L,灵敏度较好;两家单位的莱克多巴胺单克隆抗．体的特异性靳砗更好;单位1的抗体效价为1：32000,效价较高。最终选择江南大学提供的RAC-OVA抗原,原始浓度为10mg／mL,抗莱克多巴胺单克隆抗体的原始浓度为9．8mg／mL。     

4种邻苯二甲酸酯塑化剂人工抗原的合成及免疫检测

以4-硝基邻苯二甲酸为原料,衍生合成4 种结构类似物,并分别通过重氮化法和活泼酯法与载体蛋白牛血清白蛋白（bovine serum albumin,BSA）和卵清白蛋白（ovalbumin,OVA）偶联制得人工抗原。利用紫外光谱扫描和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（sodium dodecyl sulfate-polyacrylamide gel electroporesis,SDS-PAGE）检测鉴定人工抗原,并用4 种与BSA偶联的人工抗原作免疫原免疫新西兰大白兔。利用酶联免疫吸附实验（enzymelinkedimmunosorbent assay,ELISA）检测抗体灵敏度和特异性。经紫外光谱和SDS-PAGE证实人工抗原偶联成功,经免疫分析法检测抗体效价,4-氨基邻苯二甲酸二丁酯-BSA（dibutyl 4-aminophthalate-BSA,DBAP-BSA）抗体效价达到1∶64 000,4-戊二单酰邻苯二甲酸二丁酯-BSA（dibutyl 4-carboxylphthalte-BSA,DBCP-BSA）、4-氨基邻苯二甲酸二异丁酯-BSA（diisobutyl 4-aminophthalate-BSA,DiBAP-BSA）和4-氨基邻苯二甲酸二环己酯-BSA（dicyclohexyl 4-aminophthalate-BSA,DCHAP-BSA）抗体效价均达到1∶128 000。DBAP-BSA、DBCP-BSA、DiBAP-BSA和DCHAP-BSA分别对邻苯二甲酸二丁酯（dibutyl phthalate,DBP）、DBP、邻苯二甲酸二异丁酯（diisobutyl phthalate,DiBP）和邻苯二甲酸二环己酯（dicyclohexyl phthalate,DCHP）4 种抗体的IC50值为0.305、0.268、0.104、0.247 μg/mL。四者之间交叉反应率低,反应特异性较好。     

Short communication: Informative value of an ELISA applied to bulk tank milk to assess within-herd prevalence of digital dermatitis in dairy herds

The objective of this study was to assess whether an antibody ELISA applied to bulk tank milk (BTM) could be used to accurately estimate within-herd prevalence of digital dermatitis (DD). The ELISA was designed for the detection of antibodies against Treponema phagedenis-like strain V1 (PrrA antigen). The hind feet of all lactating cows from 40 commercial French dairy herds with a history of DD were scored by an observer in the milking parlor, using the 4 M-stage system. After milking, a BTM sample was collected and tested for anti-Treponema phagedenis-like antibodies using the antibody ELISA. Within-herd DD prevalence at the cow level was determined using 2 different approaches: (1) having DD lesion on at least 1 hind foot (Prev; prevalence of affected cows), and (2) having an M1 or M2 lesion on at least 1 hind foot (PrevA; prevalence of cows affected by DD in an active stage). Receiver operating characteristic analysis was used to determine both optimal within-herd DD prevalence and BTM sample to positive (S/P) ratio cut-off values. Two optimal cut-off values were identified. Herds with an S/P ratio of BTM ≤0.2 had a Prev ≤10% (sensitivity = 0.97, specificity = 1), whereas herds with an S/P ratio of BTM >0.38 had a Prev >40% (sensitivity = 0.94, specificity = 0.86). In the same way but with a slightly lower specificity, an S/P ratio >0.38 corresponds also to a PrevA >18% (sensitivity = 0.92, specificity = 0.70). The BTM antibody ELISA shows great promise for screening purposes during DD management programs.