Production of a highly group-specific monoclonal antibody against zearalenone and its application in an enzyme-linked immunosorbent assay

A monoclonal antibody (mAb) against zearalenone (ZEN) was produced using ZEN-carboxymethoxylamine and -BSA conjugates. Antibody produced by one clone showing a very high binding ability was selected and found to have a higher affinity for ZEN compared to a commerciall ZEN antibody. We developed two direct competitive ELISA systems using the selected antibody (ZEN-coated and anti-ZEN antibody-coated ELISA). Quantitative ranges for the anti-ZEN antibody-coated ELISA and ZEN-coated ELISA were from 25 to 750 ppb and from 12.5 to 100 ppb, respectively. The detection limit of both methods as measured with standard solutions was 10 ppb. The intra-plate and inter-well variation of both ELISAs were less than 10%. The IC₅₀ values for α-zearalenol, β-zearalenol, α-zearalanol, and β-zearalanol compared to ZEN were 108.1, 119.3, 114.1, and 130.3% for the ZEN-coated ELISA. These values were 100.7, 120.7, 121.6, and 151.6% for the anti-ZEN antibody-coated ELISA. According to the anti-ZEN antibody-coated ELISA, the average recovery rates of ZEN from spiked animal feed containing 150 to 600 ng/mL of ZEN ranged from 106.07 to 123.00% with 0.93 to 2.28% coefficients of variation. Our results demonstrate that the mAb developed in this study could be used to simultaneously screen for ZEN and its metabolites in feed.     

玉米赤霉烯酮单克隆抗体的制备及间接竞争ELISA检测方法的初步建立

为了研究玉米赤霉烯酮的间接竞争ELISA检测方法,试验采用牛血清白蛋白与玉米赤霉烯酮的耦联物(ZEN-BSA)做包被抗原,标准玉米赤霉烯酮(ZEN)做竞争抗原,以制备的可稳定分泌抗ZEN的单克隆抗体为基础,初步建立了ZEN间接竞争ELISA检测方法。结果表明:间接竞争ELISA检测方法线性范围为0.363 2～78.985 2μg/L,最低检测限为0.231 9μg/L;曲线回归方程为y=68.711-25.666x,其中R2=0.987 1,批内平均变异系数为3.10%,批间平均变异系数为6.26%,与相似毒素的交叉反应率均小于0.01%。说明建立的检测方法可以用于ZEN的检测。     

磺胺二甲嘧啶单克隆抗体的研制

本研究将磺胺二甲嘧啶与人血清白蛋白、卵清白蛋白联接 ,分别作为免疫原、包被原 ,建立 EL ISA筛选方法 ,并利用杂交瘤技术 ,制备了分泌抗磺胺二甲嘧啶单克隆抗体的细胞株。经鉴定的单克隆抗体的蛋白亚型为 Ig G1 ;染色体数为 88～94条 ;分子量为 170 .2 KDa;亲和常数为 2 .5× 10 1 0 M- 1 ;与其他 6种磺胺药 (SDM、SDEP、SMM、SMZ、SD、SQ)无交叉反应     

动物组织中磺胺二甲嘧啶残留检测ELISA试剂盒的研制

在建立竞争ELISA方法的基础上，首次研制出检测磺胺二甲嘧啶的单克隆抗体快速检测试剂盒，并对其检测限、精密度、检测范围以及鸡肌肉组织中的添加回收实验做了详细研究。本试剂盒的检测限为1．0ng／m1，检测范围为1．0-81．0ng／m1，批内变异系数＜8．9％，批间变异系数＜9．5％，在10、60和200ng／m1水平鸡肌肉组织中添加，回收率为64．5％-85．5％，变异系数为6．0％-18．6％。与同类相关德国产试剂盒相比较，阳性符合率为100％。     

抗氯霉素单克隆抗体的制备与鉴定

本文用人工合成的氯霉素 -牛血清白蛋白 (CAP- BSA)免疫 BAL B/ C小鼠 ,通过杂交瘤技术建立了 2株分泌抗氯霉素的单克隆抗体 (Mc Ab)的杂交瘤细胞 1D1 0 和 5 E6 。经间接酶联免疫吸附试验 (ci EL ISA)检测细胞培养上清效价为 1∶ 5 12 ,诱生腹水的效价可达 1× 10 8。两株单克隆抗体的亚型为 Ig G1 ,杂交瘤染色体数目为 84～ 96条。该细胞株体外传代和冻存复苏后抗体分泌稳定。ci EL ISA检测显示其与常见抗生素及结构类似物的交叉反应小 ,其灵敏度为 0 .1ng/ ml,IC50 为 2 .38ng/ m l,这表明该单抗具有较大的应用价值     

非洲猪瘟病毒抗体检测间接ELISA方法的建立

以基因工程表达的非洲猪瘟病毒VP73蛋白作为包被抗原,建立了间接ELISA方法,用以检测猪血清中抗非洲猪瘟VP73蛋白的抗体。该方法对非洲猪瘟标准阳性血清的检测灵敏度可以达到1∶2 560,与同类进口ELISA试剂盒相当。此方法只特异性检出非洲猪瘟阳性血清,而对猪传染性胸膜肺炎等5种猪传染病阳性血清的检测结果均为阴性,表明其具有良好的特异性。批内和批间重复性试验结果发现,检测同一份血清的变异系数小于10%,表明其重复性较好。包被好的酶标板37℃放置5d后,对同一份血清的检测敏感性无明显变化,初步表明其稳定性较好。利用建立的间接ELISA方法和进口ELISA试剂盒分别对150份血清样品进行非洲猪瘟血清抗体检测,结果表明本方法的特异性和敏感性分别为99.1%和94.3%,2种方法检测结果的符合率为98%。以上试验表明,本试验建立的间接ELISA方法具有良好的特异性和敏感性、较好的重复性和稳定性,可以满足临床检测的需求。     

Antibody responses against avian reovirus nonstructural protein sigmaNS in experimentally virus-infected chickens monitored by a monoclonal antibody capture enzyme-linked immunosorbent assay

Crude antigen preparations from avian reovirus (ARV)-infected chicken embryo fibroblasts (sigmaNS) or from bacterially expressed protein sigmaNS (esigmaNS) were captured by monoclonal antibody 1E1(MAb 1E1) against ARV nonstructural protein sigmaNS immobilized on the ELISA plates and were used as the MAb capture ELISA for antibody detection. Sixty one-week-old specific pathogenic free (SPF) chickens were divided into six groups and were vaccinated with live or inactivated ARV vaccine preparations in different combinations or inoculated with a virulent ARV strain. Sera collected from the birds were tested for their antibody responses to ARV nonstructural protein sigmaNS. Using the MAb capture ELISAs, the level of nonspecific binding reactions was tested on the serum samples obtained weekly from mock-infected SPF chickens from 1 to 25 weeks and compared to the results tested by the conventional ELISA. The results indicated that both MAb capture ELISAs had lower nonspecific bindings than those in the conventional ELISA, even in older birds. Antibody responses against ARV sigmaNS of the birds which received the inactivated vaccine twice (group I), inactivated vaccine followed by a live vaccine (group II), or a live vaccine followed by boosting with an inactivated vaccine (group III) were detected by MAb captured ELISA with sigmaNS crude antigens. The absorbance values increased rapidly at 1-2 weeks after boosting, approximated a peak at 5-6 weeks of age, and maintained this throughout the length of the experiment. The absorbance values of the MAb capture ELISA showed a good correlation to the SN titers ( r value > 0.85). On the other hand, serum samples from the birds which received the live vaccine twice (group IV) or were inoculated with a virulent ARV (group V) did not show antibody responses to sigmaNS, similar to those from the mock-infected birds (group VI), as the absorbance values maintained at a low level (below 0.5) throughout the length of the experiment. Similar results were obtained in the sera detected by MAb capture ELISA with crude esigmaNS antigens, except that the absorbance values in the sera from the birds in group III were gradually increased and later approximated a peak at 11 weeks of age and maintained this throughout the length of the experiments. The results suggest that MAb capture ELISAs can be readily used to detect antibody responses of the birds against ARV nonstructural protein sigmaNS which may reflect an immune status of a chicken flock, receiving ARV vaccine as long as including an inactivated vaccine.     

短裸甲藻毒素单克隆抗体的制备及其鉴定

采用混合酸酐法将短裸甲藻毒素(brevetoxins,BTX)分别与卵清蛋白(OVA)和牛血清蛋白(BSA)偶联制备人工抗原。以BTX-BSA作为免疫抗原免疫BALB/c小鼠,通过细胞融合-ELISA筛选抗短裸甲藻毒素的单克隆抗体,并对其特异性和灵敏性进行了鉴定。结果获得了1株可分泌短裸甲藻毒素单克隆抗体的杂交瘤细胞株3B4,该株杂交瘤细胞腹水抗体效价达10-5,与其他类似物没有交叉反应。该抗体为建立短裸甲藻毒素免疫学检测方法奠定了基础。     

大豆抗原蛋白血清抗体间接ELISA检测方法的建立

旨在建立检测血清大豆抗原蛋白抗体的间接ELISA方法。经琼脂糖凝胶层析纯化大豆抗原蛋白,以不同剂量皮下注射免疫小鼠,采用方阵滴定法确定最佳抗原包被浓度及血清稀释度,并对其他条件进行优化,最终建立检测血清大豆抗原蛋白抗体的间接ELISA方法,利用该方法检测小鼠免疫后血清抗体水平。通过方阵滴定法确定11S蛋白最佳包被浓度为5.0μg/mL,血清稀释倍数为1∶800;7S蛋白抗原最佳包被浓度为2.5μg/mL,血清稀释倍数为1∶1 600;两者的批内、批间系数均小于10%,重复性较好,通过ELISA法确定11S和7S蛋白的最佳免疫次数为2次,免疫剂量为1 000μg/kg。结果表明本试验初步建立大豆抗原蛋白抗体检测间接ELISA方法,具有很强的特异性、敏感性和重复性,可用于大豆抗原蛋白过敏反应的临床检测。     

水泡性口炎病毒单克隆抗体的制备与鉴定

将水泡性口炎病毒（VSV）经差速离心和蔗糖密度梯度离心法进行纯化后,以纯化的VSV作为免疫原免疫8～10周龄雌性BALB/c小鼠,取其脾细胞与SP2/0骨髓瘤细胞进行融合,经间接ELISA方法筛选能稳定分泌抗VSV单克隆抗体的杂交瘤细胞株,并对制备出的抗VSV单抗的特异性、抗体亚类等生物学特性进行鉴定。结果显示,试验成功筛选出2株能稳定分泌抗VSV单克隆抗体的杂交瘤细胞株,分别命名为1A2、4C3。ELISA鉴定结果表明,2株单抗均能特异性地与VSV结合,而与口蹄疫病毒（FMDV）、猪水泡病病毒（SVDV）均不发生交叉反应;诱生小鼠腹水产生的抗体效价可达1∶25 600～1∶51 200。杂交瘤细胞染色体核型鉴定结果显示,杂交瘤细胞染色体数为95～105,均高于2个亲本细胞的染色体数目,说明这2株细胞是两者的杂交产物。抗体亚类鉴定结果显示,所获得2株单抗1A2、4C3均为IgG1。Western blot分析结果表明,1A2可识别VSV G蛋白。2株抗VSV单克隆抗体的成功制备将为VSV快速检测方法的建立以及检测试剂的研制等奠定基础。     

Production and characterization of monoclonal antibodies detecting chicken interleukin-2 and the development of an antigen capture enzyme-linked immunosorbent assay

Eleven monoclonal antibodies (mAbs) which are specific for chicken interleukin-2 (chIL-2) were produced and characterized by enzyme-linked immunosorbent assay (ELISA), Western blotting and neutralizing assays. These mAbs were used to develop a mAb-based antigen capture ELISA specific for chicken IL-2 detection. Anti-IL-2 mAbs bound specifically to E. coli-derived rchIL-2 in ELISA and identified a 16 kDa IL-2 polypeptide band in Western blot. Several mAbs were shown to neutralize the biological activities of both rchIL-2 and native chicken IL-2 as measured by concanavalin A (ConA)-induced lymphocyte proliferation assay, IL-2 bioassay, and natural killer cell assay. Among the neutralizing mAbs, the mAb chIL-2/11 was most potent in neutralizing IL-2 activity. To develop a sensitive ELISA for the detection of chicken IL-2, an antigen capture ELISA was developed using the mAb chIL-2/16 as the antigen capture antibody and rabbit anti-IL-2 peptide antibody as the detection antibody. Using the mAb-based antigen capture ELISA, significant correlation between the level of IL-2 detected in bioassays and in ELISA was observed. These results showed that the mAb-based antigen capture ELISA is less time-consuming and more reliable compared to a conventional IL-2 bioassay for chicken IL-2. These neutralizing mAbs will facilitate basic immunobiological studies of the role of IL-2 in normal and disease states in chickens.     

牛尿中玉米赤霉醇残留酶联免疫检测方法的研究

在制备了玉米赤霉醇单克隆抗体的基础上 ,建立了牛尿中玉米赤霉醇残留的 EL ISA检测方法 ,确定了各种溶液的最适工作浓度 ,并对最低检测限、5 0 %抑制浓度和空白牛尿添加回收试验进行了研究。本方法的最低检测限为 0 .6 ng/ml,5 0 %抑制浓度为 3.0 ng/ml,以 10、2 1和 35 ng/ml浓度添加空白牛尿 ,回收率在 70 .0 %～ 116 .0 %之间 ,变异系数在 6 .0 %～ 15 .9%之间。此方法快速、灵敏、方便 ,满足了牛尿中玉米赤霉醇残留检测的要求     

SMD单克隆抗体的制备及测定方法的建立

用戊二醛作为偶联剂 ,将磺胺对甲氧嘧啶 (SMD )与牛血清白蛋白 (BSA )或卵清蛋白 (OVA)偶联形成完全抗原 ,经紫外分光光度计扫描鉴定。以人工抗原免疫BALB/c小鼠 ,取脾细胞与骨髓瘤细胞 (SP2 /0 -Ag1 4)融合 ,用间接ELISA联合竞争ELISA法筛选出产生针对SMD抗体的杂交瘤细胞。经克隆 ,得到 3株特异性好的阳性杂交瘤细胞 ,注入小鼠腹腔产生腹水。建立了测定SMD的ELISA法 ,其检测下限小于5ng/mL。     

抗猪附红细胞体单克隆抗体的制备

以纯化的猪附红细胞体免疫BALB/c小鼠,运用淋巴细胞杂交瘤技术进行细胞融合,并用间接ELISA方法进行筛选,经过间接ELISA方法、免疫印迹和间接免疫荧光试验进行鉴定,共获得5株分泌抗猪附红细胞体单克隆抗体的杂交瘤细胞,分别命名为1H1、1H2、3A5、5B1和7E11,其单抗亚类鉴定分别属于IgG2b、IgG1、IgG2b、IgG2b和IgG2b。这5株McAb均能与猪附红细胞体全菌蛋白发生特异性反应,而不与猪肺炎支原体、猪链球菌、大肠杆菌和猪繁殖与呼吸综合征病毒发生反应,并且1H1、3A5和5B1能识别同一抗原位点,1H2和7E11识别另一抗原位点。     

恩诺沙星在鸡肉组织中残留的ELISA检测方法研究

分别用N-羟基琥珀酰亚胺法和氯甲酸异丁酯法把恩诺沙星(ENR)与载体蛋白牛血清白蛋白(BSA)和鸡卵清蛋白(OVA)偶联制备免疫抗原和包被抗原,免疫新西兰大白兔得到ENR的多克隆抗体,建立了ENR间接竞争ELISA方法。结果表明:抗ENR血清效价达达1∶212以上,得到标准曲线的线性回归方程为Y=-0.2341X+0.1193(R2=0.9878),中值(IC50)为36 ng/mL,最低检测限(LOD)为10 ng/mL,标准曲线的线性范围为10~1000 ng/mL。批内变异系数为3.18%~7.64%,批间变异系数为9.69%~11.94%,鸡组织中的ENR的回收率为76.5%~89.42%。本试验建立的ELISA方法能够满足恩诺沙星兽药残留检测要求。     

Development and evaluation of an enzyme-linked immunosorbent assay for bovine antibody to Pasteurella haemolytica: constructing an enzyme-linked immunosorbent assay titer

A 2-stage strategy was developed and evaluated for estimating serum antibody titer by use of ELISA and a series of dilutions. In stage 1, the linear response region and least-square estimate of the assay line slope were established from 9-point dilution assays. Provided that the reading was within the linear response region, this information was used in the stage-2 estimation of titer from a single absorbance reading. Operationally, 2 fixed dilutions were selected, one suitably low and one suitably high, to provide at least one reading within the linear region. The procedure should save considerable time when a large number of assays are to be performed. Stage 1 required approximately twenty 9-point assays, but all subsequent assays required only 2 fixed dilutions.     

鹿副结核病抗体间接ELISA检测方法的建立

本研究以副结核杆菌亲和层析抗原为检测抗原,检测以草分枝杆菌抗原吸收的待检鹿血清,建立检测鹿副结核病血清抗体的间接酶联免疫吸附试验,确定其抗原最佳包被浓度为40μg/mL,血清样品稀释度为1:80,兔抗鹿IgG辣根过氧化物酶标记抗体稀释度为1:8000。经特异性试验和重复性试验证明该方法特异性高、重复性好。对不同地区4个鹿场的760头份鹿血清进行副结核病抗体检测,其中阳性61头份,阳性率为8%,获得副结核病在我国鹿群中的血清流行病学资料,从而为防制鹿副结核病提供一定的依据。     

Evaluation of an indirect enzyme-linked immunosorbent assay for screening antibody against aflatoxins

Enzyme-linked immunosorbent assay screening of antibody produced against aflatoxin was accomplished by a new and simple procedure. To demonstrate the new indirect ELISA technique used, antibody against aflatoxin M1 was produced in female BALB/CJ mice by immunization with an aflatoxin M1-bovine serum albumin conjugate. Instead of coating test-plate wells with purified antibody (direct ELISA) or synthesizing a second protein-aflatoxin conjugate (aflatoxin M1-poly-L-lysine) to coat test-plate wells, wells were coated with the readily available aflatoxin M1-bovine serum albumin and aflatoxin B1-bovine serum albumin. This method, applicable for any aflatoxin conjugated by the common cyclopentano-carboxymethoxyl-oxime technique, eliminates the more time-consuming and technically difficult portions of earlier direct and indirect ELISA. The new technique can be valuable in continued efforts toward development of new and improved immunoassays against aflatoxin metabolites.     

Development of a novel enzyme-linked immunosorbent assay to detect anti-IgG against swine hepatitis E virus

Swine hepatitis E virus (HEV) is widespread throughout pigs in both developing and industrialized countries. This virus is an important zoonotic agent and a public concern worldwide. Infected pigs are asymptomatic, so diagnosing swine HEV relies on detection of the virus or antibodies against the virus. However, several obstacles need to be overcome for effective and practical serological diagnosis. In this study, we developed an enzyme-linked immunosorbent assay (ELISA) that used a purified recombinant capsid protein of swine HEV. The potential clinical use of this assay was evaluated by comparing it with a commercial kit (Genelabs Technologies, Diagnostics, Singapore). Results of the ELISA were highly correlated with those of the commercial kit with a sensitivity of 97% and specificity of 95%. ROC (receiving operator characteristic) analysis of the ELISA data produced a value of 0.987 (95% CI, 0.977~0.998, p < 0.01). The cut-off value for the ELISA was also determined using negative pig sera. In summary, the HEV-specific ELISA developed in the present study appears to be both practical and economical.     

Detection of rotavirus in faecal specimens with a monoclonal antibody enzyme-linked immunosorbent assay: Comparison with polyclonal antibody enzyme immuno-assays and a latex agglutination test

Monoclonal antibodies have been produced against the 81/36F strain of rotavirus. One of them, was chosen as diagnostic reagent: it showed high ELISA reactivity with all the bovine, human and porcine rotavirus strains tested and reacted with VP6, structural protein product known to support the common rotavirus antigen.

A sandwich ELISA procedure using the chosen monoclonal as “capture and detecting” antibody was performed to detect rotavirus in faecal samples from experimentally inoculated newborn calves: it always gave a negative response with meconium and a positive response for the stool specimens which rotavirus have been isolated. This assay was compared with Enzygnost and Slidex Rota Kit tests and with a non-commercial sandwich ELISA test using polyclonal antibodies: it showed more sensitivity than the agglutination test and was as sensitive as the other two tests to detect rotavirus in routine diagnostic material. The test evaluated showed no equivocal results.