Detection of Atrazine Residue in Food Samples by a Monoclonal Antibody-based Enzyme-linked Immunosorbent Assay

Atrazine（AT,2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine）has been detected in ground water in several areas of the United States for many years,as well as in China,wherein the growth rate of its gross

Quantitative determination of erlotinib in human serum using competitive enzyme-linked immunosorbent assay

A selective and sensitive competitive enzyme-linked immunosorbent assay(ELISA) method was developed and validated for the quantification of erlotinib in 50 mL of samples of human serum. Anti-erlotinib serum was obtained by immunizing mice with an antigen conjugated with bovine serum albumin and 3,4-bis(2-methoxyethoxy)benzoic acid using the N-succinimidyl ester method. Enzyme labeling of erlotinib with horseradish peroxidase was similarly performed using 3,4-bis(2-methoxyethoxy)benzoic acid. A simple competitive ELISA for erlotinib was developed using the principle of direct competition between erlotinib and the enzyme marker for anti-erlotinib antibody, which had been immobilized on the plastic surface of a microtiter plate. Serum erlotinib concentrations lower than 40 ng/mL were reproducibly measurable using the ELISA. This ELISA was specific to erlotinib and showed very slight cross-reactivity(6.7%) with a major metabolite, O-desmethyl erlotinib. Using this assay, drug levels were easily measured in the blood of mice after oral administration of erlotinib at a single dose of 30 mg/kg. ELISA should be used as a valuable tool for therapeutic drug monitoring and in pharmacokinetic studies of erlotinib.

Seropositivity rates of water channel protein 4 antibodies compared between a cell-based immunofluorescence assay and an enzyme-linked immunosorbent assay in neuromyelitis optica patients

A total of 66 samples （from 27 cases with neuromyelitis optica, 26 cases with multiple sclerosis, aa 13 cases with optic neuritis） were tested for aquaporin-4 antibody by a cell-based immunofluorescence assay and an enzyme-linked immunosorbent assay. The sensitivities and specificities of the two assays were similar. We further analyzed an additional 68 patients and 93 healthy controls using the enzyme-linked immunosorbent assay. A Kappa test showed good consistency between the two methods in terms of detection of anti-aquaporin-4 antibody in the se of neuromyelitis optica patients. No significant correlations were identified with onset age or disea duration, suggesting that aquaporin-4 antibody is a good marker for neuromyelitis optica. The enzyme-linked immunosorbent assay can be used for quantifying aquaporin-4 antibody concentrations and may be useful to dynamically monitor changes in the levels of aquaporin-4 antibody during disease duration.

Development of a competitive enzyme-linked immunosorbent assay for therapeutic drug monitoring of afatinib

Afatinib is an oral tyrosine kinase inhibitor(TKI) approved for treating advanced non-small cell lung cancer. It is necessary to develop a simple quantification method for TKIs in order to facilitate therapeutic drug monitoring(TDM) in clinical settings. This study sought to develop a simple and sensitive competitive enzyme-linked immunosorbent assay(ELISA) to quantify afatinib in plasma for routine pharmacokinetic applications. An anti-afatinib antibody was obtained using(S)-N-4-(3-chloro-4-fluorophenyl)-7-(tetrahydrofuran-3-yloxy)-quinazoline-4,6-diamine(CTQD), which has the same substructure as afatinib, as a hapten. Enzyme labeling of afatinib with horseradish peroxidase was similarly performed using CTQD. A simple competitive ELISA for afatinib was developed based on the principle of direct competition between afatinib and the enzyme marker for the anti-afatinib antibody, which had been immobilized on the plastic surface of a microtiter plate. Plasma afatinib concentrations below the limit of quantification of 30 pg/mL were reproducibly measurable. Also, the values of plasma afatinib levels measured from 20 patients were comparable with those measured by high-performance liquid chromatography, and there was a strong correlation between the values determined by both methods(Y=0.976 X – 0.207, r=0.975). As indicated by its specificity and sensitivity, this newly developed ELISA for afatinib is an important tool for TDM and studies of the pharmacokinetics of afatinib.

Enzyme-linked Immunosorbent Assay for Detection of Anti-idiotype Antibodies to Antibodies to Ligand of Nicotinic Acetylcholine Receptor in Sera of Patients with Myasthenia Gravis

Anti-bungarotoxin anti-serum,which has the internal image of nicotinicacetylcholine receptor,was used as a tool to measure anti-idiotypic antibodies toantibodies to Iigand of nicotinic acctylcholine receptor in scra from 81 patients withmyasthenia gravis.Enzyme-linked immunosorbcnt assay was adopted.Thc positive ratewas 46.9%(38/81).The specific cross inhibitory test with nicotinic acetylcholinereceptor was positive.Anti-idiotype antibodies to antibodies to ligand of nicotinicacetylcholine receptor in sera of different types of myasthenia gravis patients classified ac-cording to modified Osserman’s standard and myasthenia gravis patients with or withoutthymoma were comparcd in this study and the role of anti-idiotype antibodies toantibodies to Iigand of nicotinic acctylcholinc receptor in the immunity of myasthcniagravis and the possibility of thcrapeutic use of anti-idiotype antibodies arc discussed.

Development of an Indirect Enzyme-Linked Immunosorbent Assay for Seromonitoring Contagious Bovine Pleuropneumonia Using Recombinant Lipoprotein LppQ of Mycoplasma mycoides subsp mycoides SC as Antigen

Mycoplasma mycoides subsp mycoides SC （MmmSC） is the etiological agent of contagious bovine pleuropneumonia （CBPP）. The lipoprotein LppQ encoded by lppQ gene is specific to MmmSC and is found in the type strain and in field strains isolated in Europe, Africa, and Australia, as well as in vaccine strains. No serological cross-reactions were observed with the related mycoplasmas of the Mycoplasma mycoides cluster. The N-terminal domain of the mature lipoprotein LppQ is hydrophilic, and it induces a strong, specific, early, and persistent immune response in naturally and experimentally infected animals. Mycoplasma-specific TGA （Trp） codons are utilized as stop codons in most other organisms. The lppQ N-terminal fragment from MmmSC HVRI X strain, the Chinese strain for CF antigen production, was mutated with one-step overlapping extension PCR. Sequence analysis confirmed the successful mutation from A to G in codon 198 in the lppQ gene. The fragment containing the mutation site was subcloned into the pET32a expression vector. The recombinant protein with molecular weight of 42 kDa was purified using the Ni-NTA His.Bind purification kit, with a purity of up to 95%. Western blot indicated that the standard positive serum of CBPP could react with the recombinant protein. The purified protein was diluted to 0.35 μg mL^-1, and coated to microtiter enzyme-linked immunosorbent assay （ELISA） plates. Indirect ELISA reaction conditions were optimized. The value of P/N was determined to be 4.8 （0.934/0.193）, the sensitivity to be 95.8% （46/48）, and the specificity to be 98.9% （161/163）. 3 817 cattle serum samples from three different provinces were detected by the indirect ELISA and CFT. The Kappa value is 0.63, which is middle or high agreement between the two methods.

A PRELIMINARY STUDY OF SERUM GLYCOCONIUGATES IN PATIENTS WITH CANCER USING THE ENZYME-LINKED LECTIN ASSAY

After primary analyses on the serum glycocon-jugates of lung cancer and normal individul using the enzyme-linked lectin assay (ELLA) with 12 kinds of lectins, PHA and LCA were selected to further study in the sera of 8 kinds of cancers, 4 kinds of non-malignant disease and 1 kind of postoperative cancer. It was found that the test values of 7 kinds of cancers with PHA or LCA were significantly higher than that of the normal (P<0.01); the values of 4 kinds of non-malignant diseases with PHA were not higher (P>0.05); the values of the postoperative cancer with PHA were obviously lower than that of the preoperative (P<0.05). The results showed that the serum glycoconjugates which can bind to PHA seemed related to the cancerous existence in human bodies. The significance of the findings was discussed.

ENZYME-LINKED IMMUNOSORBENT ASSAY OF HUMAN PLACENTA TYPE GLUTATHIONE S-TRANSFERASE AND ITS APPLICATION IN THE DIAGNOSIS OF HEPATOCARCINOMA

GST-π was purified from human placenta and its antiserum was raised in rabbits. The antibody IgC was purified and degraded into Fab' fragment which was conjugated with horseradish peroxidase (HRP) using N-succinimidyl-4-(N-maleimido-methyl) cyclo-hexane-1-carboxylate (SMCC) as crosslinking reagent to produce Fab'-HRP conjugate. A sandwich ELISA was established for the microquantitative determination of GST-π. The sensitivity was 11 pg/tube, which was far more sensitive than the radioimmunoassay so far reported. Using this method, the serum GST-π of 41 cases normal adult was found to be 1.06±0.94 ng/ml. The upper limit of the normal value was 2.6 ng/ml. In 30 cases of primary hepatocarcinoma, the level of serum GST-π was 24.4± 17.4 ng/ml, which was 23 times higher than the normal average value (P<0.01). The positive rate was 90%. In contrast, serum GST-π in 25 cases of chronic hepatitis was determined to be 1.74±1.16 ng/ml, which was not significantly different from the normal value (P>0.05). The pseudo-positive rate was 12.0%.

A Comparison of Enzyme-Linked Immunosorbent Assay versus Multiplex Methodology Using an <i>in Vitro</i>Model of Pulmonary Hypertension and Inflammation

Enzyme-linked immunosorbent assay (ELISA) is the most widely used method for measuring a single cytokine. Recent developments in cytokine quantification such as multiple arrays measure multiple cytokines simultaneously. Although good correlations between ELISA and multiplex methods have been observed, side by side comparisons are limited. In the present study we hypothesized that ELISA and Luminex techniques are comparable in detecting cytokines in culture medium when pulmonary artery smooth muscle cells (PASMC) are exposed to stress. Primary human PASMC were cultured in modular chambers and exposed to 21% FiO2 and peak inspiratory and positive end expiratory pressure of 24 and 8 cmH2O respectively, and 95% FiO2. At 24 hours, culture medium was collected and assayed for interleukin-6 (IL-6) and IL-8 by quantitative ELISA and by Human Cytokine 25-Plex Panel using a Luminex 200 analyzer. A comparative analysis of agreement between our ELISA and Luminex data was detailed for control and stress conditions using the Bland-Altman plot analysis. Each assay resulted in comparable increased (p < 0.001) levels of IL-6 and IL-8 as compared to control in response to oxidative and biophysical stress. The Bland-Altman analysis demonstrated that 95% of the differences between ELISA and Luminex values were within ±1.96 SD from the mean difference indicated by the 95% limits of agreement for the measurements of IL-6 and IL-8. There was no systematic bias as a function of inflammation level. We conclude that in this cell culture model, ELISA and Luminex are comparable in detecting the levels of IL-6 and IL-8 in the culture medium. If measurements of multiple cytokines are demanded and the amount of sample is limited, Luminex multi-analyte profiling technology is accurate and sensitive.

基于条件优化探索对流免疫电泳技术的实验教学设计

为了提高对流免疫电泳实验的成功率和缩短电泳时间,本实验以BSA和自制备的兔抗BSA抗血清作为实验材料,通过优化和改变电泳介质、电泳缓冲液等条件,观察比较抗原-抗体沉淀线形成的位置、形状情况来探索符合实验教学要求的过程方案。结果表明,在100 V电压下,采用TAE作为缓冲液、1.0%~1.2%的琼脂凝胶作为电泳介质时,电泳15~20分钟内可形成白色、清晰可见的抗原-抗体沉淀线,实验效果最佳。

Location-based prediction model for Crohn’s disease regarding a novel serological marker,anti-chitinase 3-like 1 autoantibodies

BACKGROUND Defective neutrophil regulation in inflammatory bowel disease(IBD)is thought to play an important role in the onset or manifestation of IBD,as it could lead to damage of the intestinal mucosal barrier by the infiltration of neutrophils in the inflamed mucosa and the accumulation of pathogens.Like neutrophils in the context of innate immune responses,immunoglobulin A(IgA)as an acquired immune response partakes in the defense of the intestinal epithelium.Under normal conditions,IgA contributes to the elimination of microbes,but in connection with the loss of tolerance to chitinase 3-like 1(CHI3L1)in IBD,IgA could participate in CHI3L1-mediated improved adhesion and invasion of potentially pathogenic microorganisms.The tolerance brake to CHI3L1 and the occurrence of IgA autoantibodies to this particular target,the exact role and underlying mechanisms of CHI3L1 in the pathogenesis of IBD are still unclear.AIM To determine the predictive potential of Ig subtypes of a novel serological marker,anti-CHI3L1 autoantibodies(aCHI3L1)in determining the disease phenotype,therapeutic strategy and long-term disease course in a prospective referral cohort of adult IBD patients.METHODS Sera of 257 Crohn’s disease(CD)and 180 ulcerative colitis(UC)patients from a tertiary IBD referral center of Hungary(Division of Gastroenterology,Department of Internal Medicine,Faculty of Medicine,University of Debrecen)were assayed for IgG,IgA,and secretory IgA(sIgA)type aCHI3L1 by enzyme-linked immunosorbent assay using recombinant CHI3L1,along with 86 healthy controls(HCONT).RESULTS The IgA type was more prevalent in CD than in UC(29.2%vs 11.1%)or HCONT(2.83%;P<0.0001 for both).However,sIgA subtype aCHI3L1 positivity was higher in both CD and UC patients than in HCONT(39.3%and 32.8%vs 4.65%,respectively;P<0.0001).The presence of both IgA and sIgA aCHI3L1 antibodies was associated with colonic involvement(P<0.0001 and P=0.038,respectively)in patients with CD.Complicated disease behavior at sample procurement was associated with aCHI3L1 sIgA positivity(57.1%vs 36.0%,P=0.009).IgA type aCH3L1 was more prevalent in patients with frequent relapse during the disease course in the CD group(46.9%vs 25.7%,P=0.005).In a group of patients with concomitant presence of pure inflammatory luminal disease and colon involvement at the time of diagnosis,positivity for IgA or sIgA type aCH3L1 predicted faster progression towards a complicated disease course in time-dependent models.This association disappeared after merging subgroups of different disease locations.CONCLUSION CHI3L1 is a novel neutrophil autoantigenic target in IBD.The consideration of antibody classes along with location-based prediction may transform the future of serology in IBD.

酶联免疫电转移印迹技术在囊尾蚴病诊断中的应用

目的 应用高度敏感、特异的酶联免疫电转移印迹技术 (EITB)诊断囊尾蚴病。 方法 用双向电泳法对囊液抗原进行分离、纯化 ,并通过免疫印迹 ,用囊尾蚴病患者、棘球蚴病患者和其他异源血清筛选高免疫反应性和高特异性抗原组分 ,以此建立EITB诊断方法 ,与传统的ELISA法相比 ,并比较血清和滤纸干血浸出液两种样本的敏感性。 结果 得到了等电点为 9.4,相对分子质量为 14 0 0 0和 1660 0两组特异性抗原组分 ,以此为诊断抗原建立了EITB诊断方法 ,其敏感度和特异度分别高达 92 .5 %和 10 0 % ,显著高于ELISA法。在EITB中血清和滤纸干血浸出液的敏感性相似。 结论 EITB诊断囊尾蚴病较ELISA法敏感性高。

对流免疫电泳在水貂阿留申病诊断中的应用进展

水貂阿留申病(AD)是一种在世界范围内广泛流行的、严重危害水貂养殖业的病毒性传染病。对流免疫电泳(CIEP)是世界公认的诊断AD病的有效方法。本文综述了CIEP在AD诊断中的应用进展,介绍了该方法的优缺点和实用性,以期为疾病的有效防控提供参考。

免疫固定电泳技术在多发性骨髓瘤单克隆免疫球蛋白检测中的应用

目的探讨应用免疫固定电泳技术检测多发性骨髓瘤单克隆免疫球蛋白(M蛋白)的意义。方法采用琼脂糖凝胶免疫固定电泳技术检测261份临床送检血清和尿液,其中76例为多发性骨髓瘤患者。结果76例多发性骨髓瘤患者血清M蛋白阳性76例,阳性率为100%;尿本周蛋白阳性53例,阳性率为70%。17例血清M蛋白为轻链型患者尿本周蛋白阳性率为94%。185例非多发性骨髓瘤患者均未检出M带。结论免疫固定电泳检测M蛋白的技术对诊断多发性骨髓瘤具有高度的敏感性和特异性,是M蛋白定性和分型的首选方法。

绿僵菌免疫特性的研究

采用免疫电泳的方法对不同来源的７株绿僵菌进行了免疫学对比研究。抗原是由菌丝体清液和孢子悬液组成，通过对家兔接种抗原而获得抗血清。每一种抗原与其同源抗血清和异源抗血清进行交叉试验，并对免疫电泳反应产生的沉淀弧数目和图谱加以对比分析。结果表明：不同菌株间存在着明显的抗原类似性，同时各菌株间也表现出一定的抗原专一性。根据实验数据对供试菌株进行分类的结果与形态学分类的结果相符合，这表明在筛选用于生物防治的丝孢菌类时，免疫电泳是揭示其内在特性的一种非常有用的方法。

火箭电泳法测定伤寒Vi多糖菌苗多糖含量

伤寒沙门氏菌Ｖｉ抗原系ａ─１，４─Ｎ─乙酰─半乳糖醛酸高度聚合体，其Ｃ２和Ｃ３位分别被Ｎ─乙酰基和０─乙酰基取代，它不能用分光光度法测定其含量，实验表明火箭电泳的火箭峰高与其样品中多糖含量的对数成直线相关关系，作者采用火箭电泳方法对全国六个生物制品研究所的１８批伤寒Ｖｉ多糖菌苗中Ｖｉ多糖含量进行了测定，结果表明多数制品符合规程要求，但部分制品多糖含量偏高，值得引起注意，各所三批制品差别不大，表明各所的生产工艺相对稳定，利用火箭电泳测定伤寒Ｖｉ多糖，操作简单，用时较短，所需样品极少，是目前较为合适的测定伤寒Ｖｉ多糖菌苗多糖含量的方法。

猪血浆转铁蛋白含量火箭免疫电泳法研究

本研究建立的测定猪血浆Tf含量的火箭免疫电泳法,具良好的一致性及重复性,灵敏度达974ng/mL,测得112例15～180日龄健康猪血浆Tf含量为2767.36～3220.66μg/mL,与双抗体夹心型ELISA结果基本吻合。因而证明,火箭免疫电泳法可有效地用于猪血浆Tf的定量分析。

食品中丙烯酰胺检测方法的研究进展

丙烯酰胺是在食品高温加工过程中产生的小分子有机化合物,具有致癌性。从样品提取、衍生化、净化、富集等前处理过程以及对检测器的选择出发,总结国内外近年来用于检测丙烯酰胺的方法,如从传统的气相色谱、液相色谱及其联用技术,到新兴开发的分子印迹技术、酶联免疫吸附和生物传感器等新检测技术。并根据其适用范围和操作条件,对各分析方法的优点和不足进行讲述,最后对将来丙烯酰胺检测方法发展新思路提供策略和依据。

水貂阿留申病诊断技术的研究进展

水貂阿留申病是由水貂阿留申病毒引起的自身免疫性疾病,目前尚无有效疫苗,每年结合打皮期筛查淘汰病貂是该病防控的主要手段。目前,水貂阿留申病的主要诊断方法是依据临床症状和血清的对流免疫电泳检测。对流免疫电泳需要在实验室内进行,使用范围局限。综述了国外该病诊断的最新研究进展,以期为该病诊断技术的开发提供思路。

几种血清学技术在浙贝母花叶病毒(Thunberg fritillary mosaic virus)检测中的应用

通过12%SDS-PAGE和5%～20%梯度SDS-PAGE二次制备电泳纯化浙贝母花叶病毒(Thunberg fritillary mosaic virus,TFMV)的外壳蛋白,4次免疫小鼠,获高纯度的抗血清。分别用Western blot、间接ELI SA、免疫扩散、火箭免疫电泳和对流免疫电泳5种免疫检测技术对TFMV样品进行了检测。结果表明,间接ELISA方法不能灵敏地检测新鲜病汁液中的病毒粒子,免疫扩散不能用于未变性病毒粒子的检测。Western blot灵敏度高,但操作复杂。火箭免疫电泳和对流免疫电泳均具有操作简单、灵敏度高、检测周期短的优点,但前者需抗血清的量大。5种免疫检测技术中,对流免疫电泳最适合浙贝母病样中TFMV的快速检测。