金标免疫层析法测定前列腺抗原方法的应用

目的：采用前列腺抗原（ＰＳＡ）单抗标记胶体金的方法。测定ＰＳＡ抗原。方法：采用柠檬酸三钠还原法制备胶体金、金标免疫层析方法（ＧＳＬＩＡ）测定。结果：将金标方法与ＥＬＩＳＡ方法进行比较灵敏度、特异性、其两者无显著性差异。金标方法可在室温放置１年以上。结论：金标免疫层析法测定前列腺抗原，是一种快速、简便、灵敏的筛选前列腺癌患者的诊断方法。     

免疫层析法同时检测孕妇TORCH—IgM抗体的研究

目的建立一种免疫层析法用于同时检测孕妇血清中TORCH—IgM抗体。方法用胶体金标记羊抗人IgM（斗链）抗体，将巨细胞病毒（CMV）、风疹病毒（RV）、弓形体（Tox）、单纯疱疹病毒Ⅱ型（HSV-Ⅱ）四种重组抗原同时包被在硝酸纤维膜上，研制出同时检测TORCH—IgM抗体免疫层析试纸条。结果自制的免疫层析法与ELISA法对比检测阴阳性血清标本，各单项指标抗-CMV—IgM、抗-RV—IgM、抗-Tox—IgM、抗-HSV-Ⅱ-IgM阳性符合率分别为85．7％、100％、100％、100％，两法总符合率分别为97．9％、100％、100％、100％。结论本方法操作简便，显示结果直观，并且特异、稳定、快速、重复性好，可用于孕妇优生优育检测。     

ELISA间接法检测肾综合征出血热患者血清中特异性抗体

以亲和层析法提取的HFRS 病毒结构蛋白为特异性抗原,建立了检测HFRS 病人血清中特异性IgM 抗体的ELISA 间接法。首先用方阵法找到抗原的最适反应浓度为25μg/ml,血清最低滴度为1∶1000。特异性反应表明,包被的病毒结构蛋白只能与     

早期诊断心肌损伤肌球蛋白胶体金免疫层析法研究

目的建立一种简便、快速、准确检测人心肌损伤的胶体金免疫层析法（GICA）。方法制备胶体金标记抗Myosin多肽抗体，抗Myosin单克隆抗体，结合垫和样品垫的处理，组装免疫层析试纸条。检测患者血清中Myosin，进行敏感性和特异性评定。结果测试条灵敏度可达5ng／mL。检测30例急性心肌梗塞（AMI）患者血清Myosin水平，并与Roche肌钙蛋白胶体金免疫层析试剂条比较，符合率达84.2％。结论本方法特异性强、灵敏度高、简便快速、可用于急性心肌损伤的早期诊断。     

SARS病毒N蛋白的表达与DNA疫苗的构建

目的：在大肠杆菌中表达SARS冠状病毒核衣壳N蛋白，并构建其DNA疫苗。方法：构建含N基因的原核表达载体pQEN，并在大肠杆菌M15中表达N蛋白。采用NP亲和层析法纯化目的蛋白。将N基因克隆入真核表达载体pSecTagB中，构建真核重组质粒pSecN。以其免疫小鼠制备抗血清，并用ELISA法检测其与大肠杆菌中表达的重组N蛋白及天然全病毒N蛋白的反应性。结果：重组N蛋白能与DNA疫苗免疫的小鼠血清以及SARS患者血清发生特异性反应；SARS—CoV病毒颗粒也可与DNA疫苗免疫的小鼠血清发生特异性反应。结论：重组N蛋白保留了病毒的一些特异性抗原表位，可作为用ELISA法检测SARS—CoV的抗原。构建的DNA疫苗可在小鼠体内产生高效价的抗SARS病毒N蛋白的特异性抗体，从而为该疫苗的开发奠定了基础。     

新疆出血热病毒核蛋白多克隆抗体的制备及其免疫学评价

目的 原核细胞中表达、纯化新疆出血热病毒BA88166毒株核蛋白(NP)并制备及鉴定抗NP蛋白的多克隆抗体.方法 采用逆转录-聚合酶链式反应(RT-PCR)扩增出BA88166毒株S基因的cDNA片段,将其构建到原核表达载体pET-32a上,形成重组原核表达质粒pET-88166S.构建好的质粒在大肠杆菌BL21(DE3)中进行诱导表达,经镍柱亲和层析法纯化NP-His融合蛋白,SDS-PAGE分析蛋白相对分子质量(Mr).用该纯化蛋白免疫新西兰白兔制备抗血清,ELISA和Western blot法检测血清效价和特异性.结果 双酶切鉴定和DNA测序证实构建的pET-88166S重组表达载体正确,目的基因序列与GenBank中公布的序列一致,在E.coli BL21中表达的NP-His融合蛋白经SDS-PAGE分析,其Mr约为66000.ELISA检测抗体效价高于1:25600,蛋白免疫印迹实验结果表明抗体能特异性识别新疆出血热病毒YL04057毒株的NP蛋白及其截短蛋白.结论 成功获得新疆出血热病毒NP-His融合蛋白,得到了特异性兔抗NP蛋白多克隆抗体.     

同时检测HIV抗体及p24抗原快速诊断试剂的研制

目的：研制可同时检测HIV－1、HIV－2抗体及p24抗原的胶体金快速诊断试剂。方法：利用重组杆状病毒－昆虫细胞系统进行HIV－1 gp41及HIV－2 gp36抗原的高效表达，以免疫亲和层析法纯化抗原。抗－HIV p24单克隆抗体杂交瘤细胞株，并制备抗－HIV p24单克隆抗体。以硝酸基纤维膜为载体，以纯化的HIV－1 gp41、HIV－2 gp36抗原及抗p24抗体点膜，20nm胶体金颗粒／抗人IgG和抗－HIV p24单克隆抗体进行标记，对33份已知HIV感染者阳性血清及6份阴性血清进行检测。结果：通过重组杆状病毒－昆虫细胞系统进行HIV－1 gp41及HIV－2 gp36抗原的表达，可获取浓度为2．0mg/L的纯化抗原。从抗p24单克隆抗体杂交瘤细胞株中培养上清液，通过葡萄球菌蛋白A免疫亲和层析柱可得到1．5mg/L的纯化抗体。利用纯化的抗原抗体进行标记，对39份已知血清进行检测，与荷兰Organon公司HIV1＋2抗体、p24抗原、ELISA诊断试剂同时检测结果进行比较，证实有较强的特异性及敏感性。结论：同时检测HIV－1、HIV－2抗体及p24抗原快速诊断试剂的问世，可为HIV感染的诊断提供一个简便、可靠、敏感的方法。     

细胞因子及特异性抗体的检测在肾综合征出血热诊断中的意义

探讨检测血清细胞因子及肾综合征出血热(HFRS) 病毒特异性抗体IgM和IgG的含量在HFRS发病机制及诊断中的意义.选择24例HFRS患者及30例健康人血清标本,采用生物素-亲和素-酶免疫技术检测IL-2、IL-6和TNF-α,ELISA方法检测血清HFRS病毒特异性抗体IgM和IgG,并对其进行统计学分析. 结果显示, ELISA法检测HFRS患者抗HFRS病毒IgM和IgG的阳性率分别为75.00 % 和50.00 %,健康对照组的抗体阳性率为零;HFRS患者血清IL-2、IL-6、TNF-α的含量分别为10.88±2.31pg/mL、256.46±102.51pg/mL和45.63±5.32pg/mL,高于健康对照组0.59±0.24pg/mL(P＜0.01)、53.8±19.21 pg/mL(P＜0.01)和5.81±3.58 pg/mL(P＜0.01). 结论 :HFRS患者血清IL-2、IL-6和TNF-α及血清特异性抗体IgM和IgG的含量较健康人明显升高,检测这些指标对该病发病机理、诊断及预后评价有一定意义.     

应用胶体金层析法快速检测鼠疫耶尔森氏菌F1抗原

目的研究胶体金免疫层析法用于鼠疫耶尔森菌的快速诊断。方法采用胶体金免疫层析测试条,加入待测鼠疫耶尔森菌液及对照菌液。结果金标免疫层析试纸条在检测中并未出现交叉反应,特异性达到100％,显示其在鼠疫耶尔森菌的检测中特异性较好,结果可靠。同时该试纸条敏感性亦较高,少量细菌或抗原就可得到阳性结果,检测效果好。结论该方法简便、快速、敏感、特异性好,适合于公共突发卫生事件中的鼠疫快速诊断和现场鼠疫监测。     

肾综合征出血热IgM抗体早期诊断两步法MacELISA的建立

目的 建立和改善肾综合征出血热早期诊断IgM抗体捕获MacELISA法.方法 汉坦病毒核蛋白重组表达纯化后用辣根过氧化物酶标记,建立一种以酶标抗原为基础的MacELISA(称为两步法MacELISA)并与常规三步法MacELISA进行比较分析.结果 检测不同病日HFRS患者血清IgM抗体比较两步法与三步法MacELISA高度相关,敏感性和特异性为100%,无有明显差别.结论 本方法操作简单,用时少,成本低,适合用于肾综合征出血热早期诊断和汉坦病毒感染的监测.     

Recombinant nucleocapsid protein-based IgG enzyme-linked immunosorbent assay for the serological diagnosis of SARS

The recombinant nucleocapsid protein (rNP) of severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) was expressed in a baculovirus system. The purified SARS-CoV rNP was used as an antigen for detection of SARS-CoV antibodies in IgG enzyme-linked immunosorbent assay (ELISA). The ELISA was evaluated in comparison with neutralizing antibody assay and the authentic SARS-CoV antigen-based IgG ELISA. Two-hundred and seventy-six serum samples were collected from health care workers in a hospital in which a nosocomial SARS outbreak took place and used for evaluation. The SARS-CoV rNP-based IgG ELISA has 92% of sensitivity and specificity compared with the neutralizing antibody assay and 94% sensitivity and specificity compared with the authentic SARS-CoV antigen-based IgG ELISA. The results suggest that the newly developed SARS-CoV rNP-based IgG ELISA is a valuable tool for the diagnosis and seroepidemiological study of SARS. The SARS-CoV rNP-based IgG ELISA has an advantage over the conventional IgG ELISA in that the antigen can be prepared by laboratory workers without the risk of infection.     

High level expression of recombinant mumps nucleoprotein in Saccharomyces cerevisiae and its evaluation in mumps IgM serology.

To develop improved reagents for mumps serology a high-level yeast expression system was employed to produce recombinant mumps nucleoprotein (rNP). The rNP was purified by CsCl gradient centrifugation and yielded approximately 15 mg/l of yeast culture. Electron microscopy of the rNP revealed characteristic herring-bone structures. The electrophoretic mobility of rNP in yeast cells was similar to native NP in SDS-PAGE. Monoclonal antibodies to rNP reacted with native mumps virus nucleoprotein by immunofluorescence assay. A monoclonal antibody to native mumps virus NP reacted with rNP by Western blot assay. The rNP was investigated as antigen in an IgM capture enzyme immunoassay (EIA) using a horseradish peroxidase conjugate of monoclonal antibody to the rNP. Eighteen sera previously found to be positive by IgM capture radioimmunoassay (MACRIA) and 30 sera that were mumps IgM negative by MACRIA were tested by mumps IgM capture EIA. The results for the two test were concordant. In addition, 26 rheumatoid factor positive sera and 35 sera that were IgM positive for measles, rubella or parvovirus B19 were tested. Fifty-nine sera were negative by mumps IgM capture EIA but two sera collected from two infants 3 and 6 weeks after mumps, measles and rubella vaccination were positive. Mumps MACRIA confirmed these results. Compared to MACRIA the overall sensitivity was 100% (20/20) and specificity was 96.8% (30/31). The yeast expressed rNP was highly immunogenic and suitable for use in IgM capture EIA for the diagnosis of mumps.     

肺炎链球菌菌体蛋白LytA和CbpA对感染小鼠的诊断价值

目的 通过基因工程技术获取肺炎链球菌自溶素(autolysin,LytA)和胆碱结合蛋白A(choline binding protein A,CbpA),探讨其对肺炎链球菌感染小鼠的血清学诊断价值.方法 根据GenBank中lytA和cbpA基因保守序列设计合成特异性引物,采用PCR技术从肺炎链球菌基因组中扩增lytA和cbpA保守序列片段;经由IPTG诱导并通过等电点洗脱方法获取纯化的重组蛋白LytA和CbpA;Western blot测定表达蛋白的抗体结合活性.以LytA和CbpA为抗原,建市ELISA反应模式测定感染小鼠血清中相应的IgG和IgM抗体,评价诊断价值.结果 成功构建了原核表达载体pET-32a(+)/lytA和pET-32a(+)/cbpA,表达的重组蛋白LytA和CbpA具有较好的抗体结合活性.实验组小鼠(肺炎链球菌感染组)IgM和IgG类抗LytA抗体滴度高于对照组(止常对照组和乙型链球菌感染对照组),差异有统计学意义(P<0.05),CbpA抗体与正常对照组差异有统计学意义,与乙型链球菌感染组差异无统计学意义(P>0.05).CbpA蛋白对感染小鼠诊断的敏感性较高(IgG:83.3%;lgM:75.0%),而LytA特异性较高(IgG:100%;IgM:100%).结论 协同利用重组蛋白CbpA诊断敏感性及LytA的特异性,对肺炎链球菌感染小鼠的血清学诊断具有一定价值,为进一步用于临床检验奠定基础.

Abstract：

Objective To obtain the pneumococcal autolysin(LytA)and choline binding protein A(CbpA)by prokaryotic expression system and investigate their diagnosis for infection caused by Streptococcus pneumoniae.Methods The specific primers were designed according to lytA and cbpA of Streptococcus pneumoniae gene sequence.lytA and cbpA were amplified by PCR form the pneumococcus genome.After IPTG inducing,the recombinant proteins were purified by electroeluting of bag filter,detected by SDS-PAGE and Western blot.Serum lgG and IgM antibodies accordingly of BALB/c mice infected with Streptococcus pneurnoniae were detected by ELISA.Results The recombinant plasmid pET-32a(+)/lytA and pET-32a (+)/cbpA were constructed successfully.Fusion proteins LytA and CbpA were expressed and displayed expected antigenicity.IgM and IgG antibodies level anti LytA were significantly higher than the control group (infections with B Streptococcus group and healthy mice),(P<0.05),but antibodies level anti CbpA did not increase as compared with group infected with B Streptococcus(P>0.05).Diagnostic sensitivity of CbpA was 83.3%(IgG)and 75.0%(IgM).Diagnostic specificity of LytA was 100%(IgG and IgM).Conclusion The synergistic use of specificity of LytA and sensitivity of CbpA may be worthy of serological diagnosis for Streptococcus pneumoniae infection,and may be used for further clinical test.     

Recombinant nucleoprotein-based enzyme-linked immunosorbent assay for detection of immunoglobulin G antibodies to Crimean-Congo hemorrhagic fever virus

The full-length nucleoprotein of Crimean-Congo hemorrhagic fever virus (CCHFV; 482 amino acid residues) was expressed as a His-tagged recombinant protein (His-CCHFV rNP) in the baculovirus system. The His-CCHFV rNP was efficiently expressed in insect cells and purified by Ni(2+) column chromatography. Using this substrate, an immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) was developed. We evaluated the sensitivity and specificity of the IgG ELISA, using serum samples previously determined to be antibody positive or negative by immunofluorescence tests on CCHFV-infected Vero E6 cells. We found very good correlation between the two tests: 87% for the positive sera (13 of 15) and 99% for the negative sera (107 of 108). These results indicate that the new IgG ELISA using His-CCHFV rNP has high sensitivity and specificity for detecting CCHFV antibodies. The CCHF patients' sera with high titers reacted only with the NP fragment containing amino acid residues between 201 and 306 in Western blotting. It is known that amino acid homologies are high in this region among various isolates. Thus, it is expected that this ELISA can detect antibodies not only for Chinese strains of CCHFV but also for other strains circulating in the world. These results suggest that the IgG ELISA system developed with the recombinant CCHFV NP is a valuable tool for diagnosis and epidemiological investigations of CCHFV infections.     

Early diagnosis of scrub typhus with a rapid flow assay using recombinant major outer membrane protein antigen (r56) of Orientia tsutsugamushi

The variable 56-kDa major outer membrane protein of Orientia tsutsugamushi is the immunodominant antigen in human scrub typhus infections. We developed a rapid immunochromatographic flow assay (RFA) for the detection of immunoglobulin M (IgM) and IgG antibodies to O. tsutsugamushi. The RFA employs a truncated recombinant 56-kDa protein from the Karp strain as the antigen. The performance of the RFA was evaluated with a panel of 321 sera (serial bleedings of 85 individuals suspected of scrub typhus) which were collected in the Pescadore Islands, Taiwan, from 1976 to 1977. Among these 85 individuals, IgM tests were negative for 7 cases by both RFA and indirect fluorescence assay (IFA) using Karp whole-cell antigen. In 29 cases specific responses were detected by the RFA earlier than by IFA, 44 cases had the same detection time, and 5 cases were detected earlier by IFA than by RFA. For IgG responses, 4 individuals were negative with both methods, 37 cases exhibited earlier detection by RFA than IFA, 42 cases were detected at the same time, and 2 cases were detected earlier by IFA than by RFA. The sensitivities of RFA detection of antibody in sera from confirmed cases were 74 and 86% for IgM and IgG, respectively. When IgM and IgG results were combined, the sensitivity was 89%. A panel of 78 individual sera collected from patients with no evidence of scrub typhus was used to evaluate the specificity of the RFA. The specificities of the RFA were 99% for IgM and 97% for IgG. The sensitivities of IFA were 53 and 73% for IgM and IgG, respectively, and were 78% when the results of IgM and IgG were combined. The RFA test was significantly better than the IFA test for the early detection of antibody to scrub typhus in primary infections, while both tests were equally sensitive with reinfected individuals.     

检测Asia I型口蹄疫病毒的胶体金免疫层析法的建立及应用

目的:建立一种快速、简便的检测AsiaⅠ型口蹄疫病毒(FMDV)的胶体金免疫层析法(GICA)。方法:采用柠檬酸钠还原法制备胶体金颗粒,用其标记纯化的AsiaⅠ型口蹄疫抗体后包被在玻璃纤维素膜上,另外将纯化的AsiaI型口蹄疫抗体和纯化的羊抗豚鼠抗体分别包被在硝酸纤维素膜上,作为检测带与质控带。玻璃纤维膜、硝酸纤维素膜按顺序组装成胶体金快速诊断试纸条,通过系列实验验证其灵敏度、特异性、重复性及稳定性。结果:研制的AsiaⅠ型口蹄疫快速检测试纸条对AsiaⅠ型口蹄疫病毒的检测灵敏度为0.116mg/L,对阳性样品进行重复性试验3次检测结果完全相同。交叉反应证实该方法与其他血清型口蹄疫抗原和猪水疱病抗原(SVD)无交叉反应。检测田间样品,GICA与反向间接血凝的定型的符合率为96.87%。稳定性实验证实试纸条可保存12个月。结论:建立的GICA是一种快速、灵敏、特异的FMD抗原检测方法,对基层现场具有广泛应用价值。     

Comparison of two rapid diagnostic assays for detection of immunoglobulin M antibodies to dengue virus

Two easy-to-use commercial diagnostic assays, a dipstick enzyme-linked immunosorbent assay (ELISA) (Integrated Diagnostics, Baltimore, Md.) and an immunochromatographic card assay (PanBio, Brisbane, Australia) were evaluated for detection of immunoglobulin M (IgM) antibody to dengue virus with an in-house IgM antibody capture microplate ELISA as a reference assay. The dipstick ELISA was based on the indirect-ELISA format using dengue 2 virus as the only antigen and enzyme-labeled goat anti-human IgM antibody as the detector. The total assay time was 75 min. The immunochromatographic card assay was based on the antibody capture format and separately measured both anti-dengue virus IgM and IgG in the same test. Colloidal-gold-labeled anti-dengue virus monoclonal antibody bound with dengue virus 1 to 4 antigen cocktail was the detector, and anti-human IgM and IgG were the capture antibodies. The total assay time was <10 min. Sera from 164 individuals classified as either anti-dengue virus IgM positive (94) or anti-dengue virus IgM negative (70) in the reference microplate ELISA with a dengue virus 1 to 4 antigen cocktail were tested in the two commercial assays. The dipstick ELISA missed 7 of 94 positive samples, for a sensitivity of 92.6%, while the immunochromatographic card assay missed two positive samples, for a sensitivity of 97.9%. Of the 70 negative samples, four were false positive by the dipstick ELISA and two were false positive in the immunochromatographic card assay, resulting in specificities of 94.3 and 97.1%, respectively. Both commercial assays provide sensitive and specific detection of anti-dengue virus IgM antibody and could prove useful in settings where the microplate ELISA is impractical.     

人心肌肌钙蛋白Ⅰ胶体金免疫层析试纸条的研制

目的建立一种简便实用胶体金免疫层析检测方法．用于人心肌肌钙蛋白I（cTnI）的快速检测。方法采用柠檬酸三钠还原法制备胶体金,以鼠源抗cTnI单克隆抗体进行胶体金标记,以兔源抗cTnI多克隆抗体固定于硝酸纤维素膜作为捕获抗体,采用免疫层析技术制备快速检测cThI胶体金免疫层析检测试纸条。并与国外生产的胶体金试剂盒作对比。结果该试纸条检测范围质量浓度为5ng／mL～1μg／mL;灵敏度质量浓度为5ng／mL：特异性：与肌红蛋白、肌酸磷酸激酶同工酶、cTnT、cTnC无交叉反应：与国外胶体金试纸条检测结果比较阳性符合率为96．4％,阴性符合率为100．0％。结论成功建立cTnI胶体金免疫层析检测方法,该方法灵敏度高,特异性强,检测速度快,适于急性心肌梗死的早期诊断及科研工作需要．     

古尔图病毒重组截短糖蛋白基因的表达及抗体的制备

目的:原核表达古尔图病毒(Guertu virus,GTV)糖蛋白截短片段(Gn、Gn1、Gn2、Gn3、Gc1和Gc2),分别纯化Gn-His、Gc1-His和Gc2-His重组蛋白并制备其多克隆抗体。方法:采用RT-PCR的方法分别扩增得到GTV DXM毒株截短糖蛋白Gn、Gn1、Gn2、Gn3、Gc1和Gc2基因片段,并将其构建到原核表达载体pET-32a(+)中,继而转化到E.coli BL21(DE3)中进行诱导表达,SDS-PAGE分析蛋白质大小。经镍柱亲和层析纯化Gn-His、Gc1-His和Gc2-His重组蛋白,用GTV阳性羊血清通过Western blot法检测重组蛋白的抗原性。用纯化的蛋白质分别免疫新西兰白兔制备抗血清,ELISA法检测血清效价。将构建的真核表达载体pcDNA3.1-Gn和pcDNA3.1-Gc1/Gc2转染至哺乳动物Vero细胞,并用间接免疫荧光法评估前述制备的兔多克隆抗体的结合活性。最后用Western blot法检测血清与重组蛋白的特异性反应能力。结果:双酶切鉴定和测序结果表明pET-32a-Gn、pET-32a-Gn1/Gn2/Gn3、pET-32a-Gc1/Gc2、pcDNA3.1-Gn和pcDNA3.1-Gc1/Gc2重组表达载体构建正确,重组表达蛋白Gn-His、Gn1/Gn2/Gn3-His、Gc1/Gc2-His相对分子质量(Mr)大小分别约为63.4×103、37.1×103、31.9×103、30.8×103、40×103和54.4×103。重组表达蛋白能够被GTV阳性羊血清所识别;获得的抗GTV Gn、Gc1和Gc2兔多克隆抗体效价分别为1∶409600、1∶204800和1∶6400。间接免疫荧光检测和Western blot结果表明制备的多克隆抗体能够与真核表达产物或重组蛋白发生特异性反应。结论:重组GTV糖蛋白Gn-His、Gc1-His和Gc2-His得到了高效表达和纯化,具有较好的免疫性。制备的多克隆抗体效价高,特异性好。本研究结果为进一步开展GTV糖蛋白生物学功能及其检测方法和疫苗研究提供参考资料。