鸡组织中氯霉素残留的气相色谱-微电子捕获检测方法研究

建立了鸡肌肉和鸡肝脏组织中氯霉素残留的气相色谱-微电子捕获检测方法。用乙酸乙酯提取样品中的药物，正己烷脱脂，乙酸乙酯液-液分配，氮气吹干后，用Sylon BFT衍生化，进配有微电子捕获检测器（μECD）的气相色谱仪测定，外标法定量。鸡肌肉组织在0．1、0．5、1．0μg／kg三个添加水平，平均回收率为90．2％～94．3％，日内变异系数在4．5％-11．6％之间，日间变异系数在7．8％～14．3％之间，检测限0．05μg/kg，定量限0．10μg/kg。鸡肝脏组织在0．2、0．5、1．0μg/kg三个添加水平，平均回收率为82．9％～90．8％，日内变异系数在7．0％～11．2％之间。日间变异系数在7．9％～14．5％之间，检测限0．10μg/kg，定量限0．20μg/kg。     

三种氯霉素ELISA检测试剂盒评价

本试验选择三种氯霉素检测试剂盒(分别产于美国(A)、英国(B)和德国(G))及不同的前处理方法对牛奶及鸡肝组织中的氯霉素残留进行检测。从B／Bo-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、样品添加试验、实际样品检测等方面对三种试剂盒及前处理方法进行对比试验，结果表明试剂盒A、B、G对缓冲液配制的药物标准液的50％抑制浓度均低于1ng／mL；三种试剂盒的检测范围分别为0．1—2．0ng／mL(A)，0．14—21．0ng／mL(B)，0．05—4．05ng／mL(G)；板内变异系数均小于11．3％，板间变异系数均小于17．4％；样品回收率在70％-120％之间。     

GC/MS离子法测定猪尿中瘦肉精残留的研究及应用

GC／MS离子法测定猪尿中盐酸克伦特罗的残留，具有很好的分离度，特征离子与谱库检索一致，匹配度高。浓度10-200ng／mL范围呈良好的线性关系（R=0．9947）；仪器检出限为5—10ng／mL；回收率范围为69．7％-97．6％；批内变异系数≤6．1％。批间变异系数≤3．2％。检测60批猪尿中盐酸克伦特罗的残留。检出率为0。本方法对确证猪尿中盐酸克伦特罗残留具有重要意义。     

猪肝和猪尿中沙丁胺醇和克伦特罗残留的酶联免疫吸附检测法研究

采用混合酸酐法将沙丁胺醇与牛血清白蛋白偶联，并免疫家兔制备抗沙丁胺醇抗血清。以间接ELISA法测定血清效价，测得抗血清最佳工作浓度为1：6400，该抗沙丁胺醇抗血清对克伦特罗有110％的交叉反应性。建立了能够同时检测SAL和CL的间接竞争ELISA方法，该方法对沙丁胺醇的检测范围为0．48ng／mL～8．0μg／mL，对克伦特罗的检测范围为0．43ng／mL～7．3μg／mL，对沙丁胺醇的检测灵敏度为o．48ng／mL，对克伦特罗的检测灵敏度为0．43ng／mL。在猪肝和猪尿中添加1～50ng／g(ng／mL)的沙丁胺醇，添加回收率为72．2％～84．8％，变异系数为4．2％～28．3％，在猪肝脏和猪尿中添加1～50ng／g(ng／mL)的克伦特罗，添加回收率为84．3％～103．4％，变异系数为O．3％～35．5％。     

HPLC法测定饲料中喹乙醇的研究

建立了饲料中喹乙醇含量的HPLC测定法，流动相为15％甲醇，流速0．9mL／min，进样量5μL，检测波长260nm。在10～100μg／mL范围内，喹乙醇浓度与峰面积呈良好的线性关系，r为0．99998，回收率85．8％～99．4％，批内变异系数≤5．7％，批间变异系数≤1．1％。24批鸡配合料中未检出喹乙醇，62批鱼饲料中喹乙醇的检出率为8．1％，含量范围为19．7～42．0mg／kg。该方法具有很好的分离度，方法简便、准确、重复性好。     

HPLC法测定饲料中喹乙醇残留及应用HPLC法测定饲料中喹乙醇残留及应用

HPLC法测定饲料中喹乙醇的残留，具有很好的分离度，浓度10～100μg／mL范围呈良好的线性关系，R=0．99998，回收率范围为85．8％～99．4％，批内变异系数≤5．7％，批间变异系数≤1．1％。实践中检测24批鸡配合饲料，喹乙醇残留未检出，检测62批鱼饲料，喹乙醇残留检出率为8．1％，检出的样品中，残留量范围为19．7～42．0mg／k。表明鱼饲料中存在喹乙醇残留隐患。     

抗IVM多克隆抗体检测牛组织中IVM残留的研究

用自制的抗伊维茵素（IVM）多克隆抗体检测牛肌肉和肝脏中IVM的残留,将IVM以5．0ng／g、10．0ng,g、20．0ng／g和40．0ng／g的量分别添加至经处理的各空白组织中,用竞争ELISA法测得IVM在肌肉和肝脏中的回收率为93．9％～98．3％,变异系数为2．1％～5．1％,最低检测限为0．94ng／g。     

生鲜乳中L-羟脯氧酸测定方法的研究

建立UV法测定生鲜乳中L-羟脯氨酸的量。浓度0-2．0μg／mL L范围呈良好的线性关系，R=0．9998。回收率范围为87．3％～107．9％，批内变异系数≤5．9％，批间变异系数≤5．6％。该方法回收率高，检出限低，工作曲线稳定．重复性好。     

恩诺沙星ELISA快速检测方法的建立

采用活酯法合成酶标记半抗原（ENR-HRP），紫外扫描分析和ELISA方法鉴定，结合比为1．6：1。选择ENR-HRP与游离ENR相竞争的模式建立检测ENR残留的ELISA检测方法，其最佳工作条件为：二抗的包被浓度为2μg／mL，抗体工作浓度1：1000，酶标半抗原工作浓度1：500。标准曲线在0．423～1000ng／mL之间线性关系良好，其IC50为33．76ng／mL，回归方程为Y=-0．07769lnx＋0．770801，相关系数r=0．99153，最低检测限0．423ng／mL。单抗对达氟沙星、培氟沙星、麻保沙星有少许交叉，特异性较好。ELISA检测方法批内平均变异系数为5．75％，批间平均变异系数为10．69％，重复性较好。     

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。     

Development of immunoassays for the detection of kanamycin in veterinary fields

Monoclonal antibody against kanamycin was prepared, and competitive direct ELISA and immunochromatographic assay were developed using the antibody to detect kanamycin in animal plasma and milk. The monoclonal antibody produced was identified to be IgG1, which has a kappa light chain. No cross-reactivity of the antibody was detected with other aminoglycosides, indicating that the monoclonal antibody was highly specific for kanamycin. Based on competitive direct ELISA, the detection limits of kanamycin were determined to be 1.1 ng/ml in PBS, 1.4 ng/ml in plasma, and 1.0 ng/ml in milk. The concentration of intramuscularly injected kanamycin was successfully monitored in rabbit plasma with competitive direct ELISA. Based on the colloidal gold-based immunochromatographic assay, the detection limits of kanamycin were estimated to be about 6-8 ng/ml in PBS, plasma, and milk. The immunochromatographic assay would be suitable for rapid and simple screening of kanamycin residues in veterinary medicine. Screened positives can be confirmed using a more sensitive laboratory method such as competitive direct ELISA. Therefore, the assays developed in this study could be used to complement each other as well as other laboratory findings. Moreover, instead of slaughtering the animals to obtain test samples, these methods could be applied to determine kanamycin concentration in the plasma of live animals.     

氯霉素间接竞争ELISA(ciELISA)检测方法的建立

以人工合成的氯霉素－牛血清白蛋白（ＣＡＰ－ＢＳＡ）为包被抗原,氯霉素（Ｃｈｌｏｒａｍｐｈｅｎｉｃｏｌ,ＣＡＰ）为竞争的半抗原,两者与一定量的抗ＣＡＰ单抗（ＣＡＰ－ＭｃＡｂ）反应。实验结果表明,理想的包被抗原浓度为１．２５μｇ／ｍｌ,抗ＣＡＰ－ＭｃＡｂ工作浓度为１：１２０００,酶标二抗工作浓度为 １： ５０００,可测最适范围为 １ｎｇ／ｍｌ－１００ｎｇ／ｍｌ,最小检测量为０．１ｎｇ／ｍｌ,批内和批间变异系数分别为３． ６２％和 ５． １９％。得到回归方程 ｙ ＝１．２７３０－ ０．６７４５ｘ（ｒ２＝ ０． ９７７９）和标准曲线,从而建立了快速定量测定 ＣＡＰ含量的间接竞争酶联免疫吸附试验（ＥＬＩＳＡ）。整个测定时间为６小时。     

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%。     

Immuno-PCR for one step detection of H5N1 avian influenza virus and Newcastle disease virus using magnetic gold particles as carriers

Detecting avian influenza virus (AIV) and Newcastle disease virus (NDV) at low concentrations from tracheal and cloacal swabs of avian influenza- and Newcastle disease-infected poultry was carried out using a highly sensitive immunological-polymerase chain reaction (immuno-PCR) method. Magnetic gold particles were pre-coated with a capture antibody, either a monoclonal anti-AIV/H5 or monoclonal anti-NDV/F and viruses serially diluted ten-fold from 10(2) to 10(-5)EID(50)/ml. A biotinylated detection antibody bound to the viral antigen was then linked via a streptavidin bridge to biotinylated reporter DNA. After extensive washing, reporter DNA was released by denaturation, transferred to PCR tubes, amplified, electrophoresed and visualized. An optimized immuno-PCR method was able to detect as little as 10(-4)EID(50)/ml AIV and NDV. To further evaluate the specificity and the clinical application of this IPCR assay for AIV H5N1 and NDV, the tracheal swab specimens, taken from chickens which were infected with H5N1/AIV, H9N2/AIV, H7N2/AIV, NDV, IBDV, IBV/H(120), were detected by IPCR. Our data demonstrated that this monoclonal antibody-based immuno-PCR method provides a platform capable of rapid screening of clinical samples for trace levels of AIV H5 and NDV in one step.     

Direct competitive enzyme-linked immunosorbent assay for sulfamethazine

A direct competitive enzyme-linked immunosorbent assay (ELISA) for screening sulfamethazine (SMZ) in pork tissues was developed. The assay was made with the affinity-purified polyclonal antibody-coated microtiter plate. A cross reactivity of IgG was observed at 3.5 microg/g of sulfamerazine among nine kinds of sulfonamide tested. Pork tissues fortified with SMZ was mixed with octadecyl silica (C18), and extracted with dichloromethane. The extracted SMZ was measured by homemade ELISA, commercial ELISA, and HPLC. The results were correlated (r=0.993, p<0.01). The homemade ELISA was sensitive to determine SMZ at the maximum residue level (MRL) as commercial one. During stability test of the IgG coated microtiter plate performed at 40 degrees C for 14 days, no difference in sensitivity was observed. We developed homemade ELISA with a detection limit of 10 ng of SMZ per g of pork tissues, and it could be used to screen SMZ in pork tissues.     

Measurement of canine IgE using the alpha chain of the human high affinity IgE receptor

In vitro assays for allergen specific immunoglobulin E (IgE) are a convenient and reproducible alternative to intradermal skin testing in dogs. Such tests may be used to support a diagnosis of atopic dermatitis and to define appropriate allergens for immunotherapy. Current in vitro assays rely upon monoclonal or polyclonal antibodies as IgE detection reagents. However, in sera where allergen-specific IgG occurs in great excess, any IgE:IgG cross-reactivity of the detection reagent may result in lowered assay specificity. Therefore, we have developed an assay for canine IgE which uses a recombinant form of the extracellular part of the alpha chain of the human high affinity IgE receptor (FcvarepsilonRIalpha). Biotinylated FcvarepsilonRIalpha shows no significant binding to purified canine IgG, and recognizes a heat labile antibody in serum, with a detection limit of 73-146pg/ml. Comparison of assay signals using the labeled FcvarepsilonRIalpha and a highly specific anti-canine IgE monoclonal antibody (MAb) shows good agreement. The FcvarepsilonRIalpha is therefore a sensitive and specific alternative to polyclonal or monoclonal antibodies for canine serum IgE measurement.     

氟喹诺酮类药物胶体金试纸的研制

用针对抗氟喹诺酮类(fluoroquinolones,FQs)药物的广谱性单克隆抗体建立了可以同时检测11种FQs药物的胶体金免疫层析方法。该试纸条用20 nm的胶体金标记单抗,将诺氟沙星－卵清蛋白喷涂在检测线上,羊抗小鼠二抗喷涂在质控线上。该胶体金试纸对猪肉和虾中环丙沙星、恩诺沙星和氧氟沙星的检测限都是30 ng/g,对诺氟沙星、培氟沙星、依诺沙星、麻保沙星、洛美沙星、达氟沙星、沙拉沙星和二氟沙星8种药物在以上两种样品中添加浓度为100 ng/g时都可被检出,整个检测过程包括样品前处理的时间可在20 min内完成。试验结果表明符合对这11种FQs药物在鸡肉和虾中残留现场大量筛查的要求。     

苯乙醇胺A单克隆抗体的研制及ELISA检测方法的建立

为制备苯乙醇胺A(phenylethanolamine A,PA)单克隆抗体,建立一种针对苯乙醇胺A的快速、简便、灵敏度高的检测方法,本试验采用重氮化法将制备的苯乙醇胺A衍生物分别与牛血清白蛋白(BSA)和卵清白蛋白(OVA)进行偶联作为免疫原和包被原。利用弗氏佐剂充分乳化免疫原(PA-BSA),按常规免疫程序免疫6～8周龄的雌性BALB/c小鼠,选择血清抗体效价较高的小鼠,取其脾细胞与SP2/0骨髓瘤细胞以PEG法进行细胞融合。结果显示,经3次细胞亚克隆筛选后,最终筛选出一株可稳定分泌抗苯乙醇胺A单克隆抗体的杂交瘤细胞株,命名为D6H8,利用此细胞以小鼠体内诱生法制备抗体。经鉴定,D6H8腹水抗体亚型为IgG1,轻链为κ链;纯化后的抗体与沙丁胺醇、盐酸克伦特罗、盐酸异丙肾上腺素和盐酸去氧肾上腺素均无明显的交叉反应(CR<0.18%),表明该抗体特异性良好。利用此抗体建立针对苯乙醇胺A药物残留检测的间接竞争ELISA方法,结果表明,腹水抗体效价为1∶12 800,猪肉中苯乙醇胺A添加浓度在5～1 000 ng/mL时线性关系良好,标准工作曲线为y=0.3861x-0.1845 (R^2=0.990),其IC₅₀为58.88 ng/mL,LOD为3.83 ng/mL,回收率在85.96%～104.32%之间。综上所述,本试验成功建立了检测苯乙醇胺A药物残留的间接竞争ELISA方法,该方法灵敏度高、稳定性较好。     

沙拉沙星间接竞争化学发光酶联免疫检测方法的建立

为建立动物源性食品中沙拉沙星（SAR）残留的快速检测方法,本试验通过对盐酸沙拉沙星进行分子改造和偶联蛋白合成完全免疫原,免疫小鼠制备SAR单克隆抗体。通过棋盘法确定最佳包被原浓度及一抗稀释度,优化确定最佳反应条件,从而建立间接竞争化学发光酶联免疫（ic-CLEIA）检测方法,并通过灵敏度、精密度、交叉反应率、添加回收试验对该方法进行评价。紫外扫描结果显示,完全免疫原偶联成功;制备的SAR单克隆抗体效价达1：4×10⁶;包被原浓度为0.25 μg/mL,抗体稀释比为1：750 000,4 ℃包被过夜,5%脱脂乳封闭,竞争孵育1 h,酶标二抗稀释比为1：10 000,孵育1 h为ic-CLEIA最佳反应条件;建立的ic-CLEIA方法标准曲线呈线性,线性范围为0.0625~10 ng/mL,R²=0.995,灵敏度IC₅₀为1.45 ng/mL;其平均批内和批间变异系数均<10%;除与二氟沙星的交叉反应率达到98.08%以外,与其他氟喹诺酮类药物的交叉反应率均<8%,与其他非氟喹诺酮类药物均无交叉反应;SAR标准溶液的最低检测限（LOD）为0.32 ng/mL,SAR在鸡肉样品中的LOD为0.46 μg/kg;添加回收率在88.3%~106.7%范围内,其变异系数≤12.2%。结果表明,本研究建立的ic-CLEIA方法检测速度快、灵敏度高,适用于动物源性食品中SAR残留的大量检测,为SAR残留检测提供了新的方法。     

Surfactant proteins in bronchoalveolar lavage fluid of horses: assay technique and changes following road transport

An enzyme-linked immunosorbent assay (ELISA) was developed for equine surfactant proteins SP-A and SP-D in bronchoalveolar lavage fluid (BALF). Anti-equine SP-A or SP-D monoclonal antibodies (mAb) were produced by hybridoma technology, purified by the antibody purification reagent, and analysed by Western blotting analysis. The immunoreaction (two-site sandwich ELISA) with a mAb, peroxidase-labelled mAb and BALF sample was carried out simultaneously and analytical recovery and precision were assayed. Six mAb for SP-A and four mAb for SP-D were successfully cloned in limiting dilution to monoclonality. These mAb were reacted with equine SP-A or SP-D on Western blotting analysis. For SP-A, a combination of solid-phase TA08 and horseradish peroxidase (HRP)-conjugated WA28 was found to be more sensitive than other combinations, gave a good dose response and was capable of measuring 0.78 to 100 ng of protein/ml. For SP-D, a combination of solid-phase TD13 and HRP-conjugated WD19 was found to be more sensitive than other combinations, had a good dose response and was capable of measuring 0.78 to 200 ng of protein/ml. The assay was used to determine the effect of 41 hours of road transport on the concentrations of SP-A and SP-D in the BALF of 30 horses. The concentrations of SP-A and SP-D decreased by 55 per cent and 36 per cent, respectively, decreases similar to the decrease in phosphatidylglycerol concentration previously reported by the authors.