可乐定ELISA检测试剂盒的研制及其性能评价

本研究通过制备可乐定完全抗原,免疫新西兰大白兔,得到特异性多克隆抗体,并和HRP标记的羊抗兔,构建间接ELISA检测法试剂盒,并进行性能测试评价。结果表明,吸光度百分比值与赛庚啶质量浓度的对数在0.1-8.1μg/L呈线性关系,相关系数R₂为0.977,半数抑制浓度(IC₅₀)为0.675μg/L,检测限为0.2μg/L,回收率为81% ～109%,具备良好的特异性,可用于动物尿样、血清和组织中的可乐定残留检测。     

QuEChERS-高效液相色谱-串联质谱法测定乳粉中黄曲霉毒素B1和M1

建立QuEChERS结合高效液相色谱-串联质谱测定乳粉中黄曲霉毒素B₁(aflatoxin B₁,AFB₁)和黄曲霉毒素M₁(aflatoxin M₁,AFM₁)的检测方法。方法 乳粉用水复溶,乙腈提取,十八烷基键合硅胶和无水硫酸镁净化,在InertSustain-C₁₈柱(2.1 mm×150 mm,3μm)上分离,乙酸铵溶液-甲醇为流动相,梯度洗脱,电喷雾正离子模式扫描,多反应监测,基质添加外标曲线定量。结果 乳粉中AFB₁和AFM在0.08~20 μg/kg浓度范围内线性关系良好,r＞0.999。检出限为AFM₁ 0.02 μg/kg,AFB₁ 0.03 μg/kg,定量限均为0.05 μg/kg。在定量限的1、5和10倍添加浓度下,平均回收率为91.5%~100.7%。结论 本方法便捷高效、重现性好、结果准确,可以为日常乳粉中黄曲霉毒素检测提供技术参考。     

雌二醇人工抗原的合成及间接竞争ELISA标准曲线的建立

琥珀酸酐法将雌二醇(E2)衍生化,再用碳二亚胺法(EDC)将半抗原与BSA和OVA偶联,制备免疫原和检测抗原,紫外扫描和红外光谱鉴定表明人工抗原合成成功,E2与BSA偶联比为12.3∶1。将E2-BSA免疫BALB/c小鼠,细胞融合技术筛选抗E2杂交瘤细胞株,制备单克隆抗体。结果表明,筛选的3株杂交瘤细胞E2D5、E3F7和E4A6抗体效价均在8×104以上。以E3F7细胞株建立间接竞争ELISA(icELISA)标准曲线,其线性范围为0.06⁶6.2μg/L,检测限和IC50值分别为0.03和0.76μg/L,除与去氢甲睾酮22.9%的交叉反应率外,与其他化合物无交叉反应。本研究为开发ELISA试剂盒,检测食源性动物产品中E2残留奠定基础。     

苯乙醇胺A人工抗原的合成及鉴定

采用重氮化法将苯乙醇胺A分别与牛血清白蛋白(BSA)和卵清白蛋白(OVA)偶联,制备免疫抗原苯乙醇胺A(PEAA)-BSA和检测抗原PEAA-OVA。经紫外扫描法和SDS-PAGE鉴定表明偶联成功,偶联比分别为15∶1、17.4∶1。用PEAA-BSA免疫BALB/c小鼠,采用间接ELISA法检测抗体效价,采用竞争ELISA法检测IC50值,获得了效价4.1×105以上、IC50值为0.2μg/L的多抗血清,证明合成了具有免疫原性的人工免疫原。     

鸡肌肉组织中左氧氟沙星残留ELISA检测方法的研究

用N-羟基琥珀酰亚胺法把左氧氟沙星(LVL)与牛血清白蛋白(BSA)偶联制备免疫抗原,免疫新西兰大白兔得到LVL的多克隆抗体,建立了LVL间接竞争ELISA方法.结果表明:抗LVL血清效价达1: 212以上,得到标准曲线的线性回归方程为y=-0.289 4x+0.049 5(R2=0.987 8),50%抑制浓度(IC50)为64 ng/mL,最低检测限(LOD)为10 ng/mL,标准曲线的线性范围为10～1 000 ng/mL.批内变异系数为3.51%～7.46%,批间变异系数为8.66%～11.89%,鸡肌肉中的LVL添加浓度在10～1 000 ng/ml范围内时,回收率为73.5%～84.36%.本试验建立的ELISA方法能够满足左氧氟沙星兽药残留检测要求.     

达氟沙星间接竞争ELISA检测方法的建立

将达氟沙星（danofloxacin, DFLX）与牛血清白蛋白(BSA)、卵清白蛋白(OVA)偶联分别作为免疫原与包被原, 达氟沙星为竞争的半抗原，建立间接竞争ELISA检测方法。试验结果表明,理想的包被抗原浓度为1.25 μg/L, 多抗(DFLX-PcAb)工作浓度为1∶10000,酶标二抗的工作浓度为1∶4000,最适检测范围为0.1～10 ng/L,最低检测限为0.2 ng/L, 批内和批间变异系数分别为3.81%和6.25%。得到回归方程y=0.7975-0.125x（R2=0.989）和标准曲线，从而建立了DFLX的快速检测残留的间接竞争酶联免疫吸附试验（ci-ELISA）。     

牛奶中替米考星间接竞争酶联免疫吸附检测法的建立

本研究通过棋盘法优化替米考星抗体、包被原浓度,并考察了最佳包被条件,最佳反应温度、时间和酶标二抗最佳反应时间等,建立了替米考星残留的间接竞争酶联免疫吸附试验(ELISA)并应用到牛奶样本的检测。建立的间接竞争ELISA方法半数抑制浓度(IC₅₀)为2.1 ng/mL,牛奶中替米考星的最低检测限(LOD)为2 μg/L。在5、10和20 μg/L添加浓度下,回收率为79.2%~90.1%,变异系数不高于9.0%。与其他常见的大环内酯类药物无交叉反应。本研究建立的替米考星间接竞争ELISA方法灵敏度达到了残留限量标准要求,为开发可用于牛奶中替米考星的快速检测试剂盒奠定基础。     

倍他米松ELISA检测方法的建立

为建立倍他米松(BET)ELISA检测方法,先使BET与琥珀酸酐反应,再采用活化酯法与牛血清白蛋白(BSA)偶联制备免疫原;其次,利用免疫动物获得多克隆抗体,经Sephrose 4B-proteinA方法对抗体进行纯化;最后,建立倍他米松ELISA检测方法。结果表明,免疫抗原偶联成功,获得了亲和力较高的多克隆抗血清,间接竞争ELISA测定其滴度为102 400、IC15为6.60×10-5 ng/mL和IC50为0.97ng/mL。该方法适用于残留在动物性食品中的BET现场大批量检测。     

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。     

抗大田软海绵酸单克隆抗体的制备与间接竞争ELISA的建立

用大田软海绵酸(okadaic acid,OA)与牛血清白蛋白(BSA)的偶联物OA-BSA作为免疫原,采用淋巴细胞杂交瘤技术制备OA单克隆抗体,并以纯化的抗体为探针建立了检测OA的快速、灵敏、简便的间接竞争ELISA(ciELISA)。回归方程和相关系数分别为:y=-0.3949x+0.6312,R2=0.9806;线性范围为0.3125~20 ng/mL;对OA的最低检出质量浓度为0.175 ng/mL;批内和批间变异系数分别为2.09%和3.27%;扇贝肉样的添加回收率为74.2%~80.8%;与鳍藻毒素(DTX1)的交叉反应(CR%)为51.82%,与石房蛤毒素(STX)无交叉反应。结果表明,建立了OA间接竞争ELISA检测方法,可用于海产品中OA残留检测。     

The Mycobiota and Toxicity of Equine Feeds

Feed contamination can lead to nutrient losses and detrimental effects on animal health and production. The purposes of this study were to investigate the mycobiota in equine mixed feeds and to determine natural contamination with aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁). Fungal enumeration of equine feed samples was done. A commercially available enzyme-linked immunosorbent assay kit was applied to quantify AFB₁ and FB₁. A comparison between ELISA and HPLC was carried out. Feed mould counts ranged from <1× 10² to 1× 10⁵ cfu/g. The most frequent genus isolated was Aspergillus (40.54%), followed by Penicillium (18.38%) and Fusarium (16.22%). The most prevalent Aspergillus sp. was A. flavus (36%). AFB₁ values ranged between 0.01 and 99.4 μg/kg. FB₁ levels ranged between 0.01 and 7.49 μg/kg. HPLC and ELISA methods showed positive correlation for AFB₁ and FB₁ determinations (r = 0.9851 and r = 0.9791, respectively). The ELISA analytical method was efficient for AFB₁ and FB₁ detection. The scarcity of studies on natural fungal contamination and on the presence of AFB₁ and FB₁ in materials used as equine feed ingredients highlights the value and contribution of this study.     

动物源性食品中齐帕特罗一步法ELISA试剂盒的研制

本研究依据直接竞争ELISA原理建立了齐帕特罗一步法ELISA试剂盒。以齐帕特罗与载体蛋白偶联物作为免疫原免疫新西兰大白兔制得齐帕特罗多克隆抗体,棋盘包被法确定其最佳抗体包被浓度、酶标抗原工作浓度、包被条件、反应时间、底物显色时间等,并对试剂盒的各项技术指标进行确认。结果表明,成功组装了齐帕特罗一步法ELISA试剂盒,并建立了尿液、饲料、奶粉和奶汁,以及组织等样品的前处理方法,检测限均远低于1 μg/kg。该试剂盒线性检测范围为0.15～10 ng/mL,IC₅₀浮动范围0.43～0.79 ng/mL,样品板内、批内、批间的变异系数均小于15%,平均回收率在70%～110%之间,与其同类药物的交叉反应率均小于0.1%。提示,本试验研制的试剂盒重复性、特异性、稳定性等各项指标均符合技术要求,可用于动物源性食品中齐帕特罗药物残留的检测。     

多西环素人工抗原的合成与鉴定

将多西环素（doxycycline,DOX）进行化学修饰引入羧基或氨基等活性基团,然后与牛血清白蛋白（BSA）和卵清蛋白（OVA）偶联合成人工免疫原DOX—PABA—BSA、DOX—BSA和包被原DOX—PABA—OVA、DOX～OVA,并用紫外吸收（UV）、凝胶电泳（SDS—PAGE）和EUSA方法对人工抗原进行鉴定;将合成的人工抗原DOX—PABA—BSA、DOX—BSA分别免疫BALB／C小鼠,用间接ELISA方法测定多抗（pAb）效价,用竞争ELISA方法鉴定其敏感性,用交叉反应试验鉴定其特异性。结果表明,二个免疫组6只小鼠血清抗体效价均在1：6400以上,DOXpAb对DOX的50％抑制浓度（IC50）在39．79～53．13μg/L,抗血清与四环素类药物交叉反应很低。本实验为建立多西环素ELISA残留免疫学检测方法和并制备多西环素试剂盒奠定了基础。     

国内外克伦特罗ELISA检测试剂盒评价

根据B/B0-50%抑制浓度、检测范围、标准溶液浓度梯度、板内变异、板间变异、样品添加检验、实际样品检验等方面的比较结果对两种克伦特罗ELISA检测试剂盒(A: 中国兽医药品监察所研制, B: 德国 r-Biopharm公司研制)进行评价。结果表明,试剂盒A的50%抑制浓度低于1.0 ng/mL; 检测范围在0.10~3.0 ng/mL之间;标准溶液浓度梯度中包括1.0 ng/mL这一限定值;板内变异系数小于13.7%,板间变异系数小于8.8%;样品回收率在70%~110%之间;实际样品检验和试剂盒B检样的阳性符合率为95.5%。试验证明,试剂盒A与试剂盒B的水平相当。     

Effectiveness of maifanite in reducing the detrimental effects of aflatoxin B1 on hematology,aflatoxin B1 residues,and antioxidant enzymes activities of weanling piglets

A feeding trial was conducted to evaluate the effectiveness of maifanite, which is mainly composed of aluminosilicate, in reducing the adverse effects of aflatoxin B₁ (AFB₁) on hematology, AFB₁ residues, and antioxidant enzymes activities in weaning piglets. A total of 32 (9.28±0.17 kg BW) individually housed crossbred piglets (Duroc×Landrace×Large white) were randomly allotted to 1 of 4 dietary treatments in a 2×2 factorial arrangement with 8 replicates per treatment. The dietary treatments included 2 AFB₁ levels (5.3 and 372.8 μg/kg) and 2 maifanite levels (0% and 1%). No differences in average daily gain, average daily feed intake, and gain to feed ratio were observed among treatments. Ingestion of the AFB₁-contaminated (AF) diets (372.8 μg/kg of AFB₁) reduced (P<0.05) the numbers of neutrophil, monocyte, and total leukocyte. There were no effects of AFB₁ on gamma glutamyltransferase, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase activities, and total protein, albumin, urea N, total bilirubin, IgG, IgA, and IgM concentrations in serum. Aflatoxin B₁ was found in the liver and kidney of piglets fed the AF diets. Piglets fed the AF diets reduced (P<0.05) the total superoxide dismutase, glutathione peroxidase, and catalase activities in serum. However, total superoxide dismutase activity in the liver was increased (P<0.05) in piglets fed the AF diets compared with those fed the basal diets (5.3 μg/kg of AFB₁). There was an interaction (P=0.003) in erythrocyte, but piglets fed the diets containing maifanite had greater erythrocyte and lymphocyte (P=0.035) numbers than those fed the diets without maifanite. The AFB₁ levels in the liver and kidney of piglets fed the AF diet containing maifanite were 29.6% and 41.2% lower, respectively, than those of piglets fed the AF diet alone. Although there was an interaction (P=0.011), piglets fed the diets containing AFB₁ and maifanite had greater serum T-SOD activity compared with those fed the diets with no maifanite. In conclusion, the addition of maifanite to the AF diet resulted in partial restoration of hematology and antioxidant enzymes activities and reduced AFB₁ levels in the liver and kidney.     

动物源性食品中泰乐菌素残留ELISA试剂盒的研制

采用杂交瘤技术,筛选并克隆出能够稳定分泌抗泰乐菌素（TYL）单抗的杂交瘤细胞株,免疫BALB／c小白鼠制备抗泰乐菌素单克隆抗体,建立泰乐菌素竞争ELISA检测试剂盒。结果表明,logit／log拟合标准曲线为y=-1．84x＋2．02,相关系数r=0．9944,线性检测范围为1．5～121．5ug／L,半数抑制浓度（IC50）为10.3ug／L,灵敏度为1．5ug／L,检测限为1．5～3．0ug／L;肌肉、肝脏、蜂蜜的添加回收率分别为64％～99％、61％～102％、60．5％～95％;平均批内和批间变异系数均小于10％;泰乐菌素与替米卡星（TIL）的交叉反应为40％,与其他类抗生素无交叉反应;此泰乐菌素试剂盒在4℃可保存6个月以上。本文建立的竞争ELISA检测方法可用于动物源性食品中泰乐菌素残留的定量检测。     

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.     

磺胺二甲基嘧啶残留检测ELISA方法的研究

本实验对磺胺二甲嘧啶残留检测ELISA反应的各种条件进行了筛选优化,建立了直接竞争ELISA检测方法,该法最小检出量为1.97ng/mL,检测范围5ng/mL～200ng/mL,样品添加回收率为73.20%～91.16%,批内变异系数<5.5%,批间变异系数<9%。与美国进口Max Signal试剂盒相比较,灵敏度为100%,特异性为96.0%,两者的符合率为98.3%。     

饲料中沙丁胺醇酶联免疫前处理方法的探究

为探讨酶联免疫法(ELISA)检测饲料中沙丁胺醇(salbutamol,SAL)的前处理方法,试验对提取液的pH、离子强度、有机溶剂浓度及样品稀释倍数等条件进行了考察,选取最适宜的提取液条件对2种不同类型的饲料样本进行提取,用ELISA测定样品中沙丁胺醇的残留量。结果表明,沙丁胺醇标准曲线的IC₅₀值为0.606 ng/mL,线性范围为0.221～1.658 ng/mL,R²=0.9998,提取液的pH为7.5,PBS缓冲液最优浓度为0.06 mol/L,稀释倍数为10倍,2种不同类型的饲料样本的检测限(LOD)为5.0 ng/mL。当沙丁胺醇的添加浓度为5、10 μg/kg时,该方法的添加回收率为77%～110%,变异系数<8%。     

Lactobacillus plantarum BS22 promotes gut microbial homeostasis in broiler chickens exposed to aflatoxin B1

Probiotics promote the health of the host by maintaining intestinal microbial homeostasis. This study aimed to investigate the benefits of Lactobacillus plantarum BS22 (LP) in the gastrointestinal tract (GIT) microbial homeostasis of broiler chickens exposed to aflatoxin B₁ using the PCR‐DGGE, viable count and real‐time PCR. The toxin adsorption experiment demonstrated that treatment R5 (1.0 × 10⁸ CFU/g LP) exhibited good absorptive effect in adsorbing the aflatoxin B₁ (AFB₁) in vitro. DGGE showed that the composition and structure of gut microbiota were more similar in the mucosa than in the content of all the samples. In addition, higher diversity of the microbiota was observed in the caecum and glandular stomach than in other segments. Lactobacillus, Enterococcus and Enterobacteriaceae were more abundant in the ileum than in the other segments. Enterobacteriaceae in groups I (basal diet) and II (basal diet+50 μg/kg AFB₁) showed a significant difference in group III (basal diet + 50 μg/kg AFB₁ + 1 × 10⁸ CFU/g LP) in the crop content and duodenum mucosa (p < .05). This investigation indicates that the L. plantarum BS22 promotes GIT microbial homeostasis in broiler chickens exposed to AFB₁, particularly for the intestine mucosa microbiota. Thus, L. plantarum BS22 is a possible candidate for degrading AFB_1.