Reports manifest a continuing need for the development of rapid and on-site (point of care) assays. Current diagnostic methods commonly used for detection of antibodies and antigens have significant limitations. Scien...Reports manifest a continuing need for the development of rapid and on-site (point of care) assays. Current diagnostic methods commonly used for detection of antibodies and antigens have significant limitations. Scientists at Micro Detect, Inc. have developed an innovative diagnostic device (method) that can be utilized broadly for antibody/antigen interactions including diagnostic assays in the medical, veterinary and food industries. The developed device can be utilized for the detection of antibodies against a single antigen or vice versa. It can also be tailored for specific panels that detect antigens or antibodies for diverse infectious agents, proteins, hormones, tumor markers, autoimmune markers, and allergens. Additionally, it can also be used for detection of toxins, antitoxins, nucleic acids, enzymes, drugs, etc. in both humans and animals. Specimens used in different formats of the device can be tears, saliva, whole blood, serum, plasma, urine, stool, and other bodily discharges. The good intra and inter precisions and acceptable linearity of the device support reliable use of the device. The CV of the device is 1.9% - 2.2%. Likewise, the performance of the device using 92 confirmed negative and positive specimens via a typical assay showed 100% sensitivity, 80% specificity, 96.8% efficacy, 80% positive predictive value, and 100% negative predictive value. The results of our feasibility study suggest reliable utility of a device for rapid, easy-to-use, inexpensive, and on-site (point of care) diagnostic assays. This presents a potential breakthrough in diagnostic methodologies that can be integrated into modern medicine and food industries.展开更多
Merozoite surface antigens can induce protective immune responses and may becandidate antigens for malaria vaccine.Four hybridoma cell lines secreting monoclonalantibodies against Plasmodium falciparum Fcc7801/HN were...Merozoite surface antigens can induce protective immune responses and may becandidate antigens for malaria vaccine.Four hybridoma cell lines secreting monoclonalantibodies against Plasmodium falciparum Fcc7801/HN were produced.Antibodies fromthree of the four lines showed significant growth-inhibiting effect on P.falciparum invitro.One monoclonal antibody,known as C6,conjugated the antigen located exclusivelyon the merozoite surface and distributed evenly over the entire surface,as wasdemonstrated by immunoelectron microscopy.C6 also precipitated a single protein of Mr71000.展开更多
目的建立间接竞争酶联免疫吸附测定法快速筛查药酒中双氯芬酸(diclofenac,DCF)。方法采用活性酯法和混合酸酐法分别将DCF与载体蛋白耦合,得到DCF的免疫原和检测抗原。采用DCF-牛血清白蛋白免疫BALB/c小鼠,随后用杂交瘤等技术制备抗DCF...目的建立间接竞争酶联免疫吸附测定法快速筛查药酒中双氯芬酸(diclofenac,DCF)。方法采用活性酯法和混合酸酐法分别将DCF与载体蛋白耦合,得到DCF的免疫原和检测抗原。采用DCF-牛血清白蛋白免疫BALB/c小鼠,随后用杂交瘤等技术制备抗DCF单克隆抗体(monoclon alantibody,mAb),基于DCFmAb建立了间接竞争酶联免疫吸附测定法,对该检测方法的性能(准确度、精密度和特异性)进行鉴定。结果紫外扫描结果表明DCF已成功与载体蛋白偶联;获得最优株抗DCF的杂交瘤细胞株(4B9),其IC50值为0.61ng/mL;该检测方法在药酒中的DCF平均添加回收率为85.9%,其批间变异系数(coefficient of variation,CV)(5.3%~9.7%)均大于批内CV(4.9%~9.1%),与类似物(酮洛芬、阿司匹林、吲哚美辛、布洛芬、舒林酸、萘普生、罗非昔布)没有交叉反应。结论本研究建立的间接竞争ELISA法为DCF在药酒中的残留提供了一种新的筛查手段。展开更多
A competitive enzyme-linked immunosorbent assay （ELISA） suitable for the determination of the urea herbicide isoproturon, 3-（4-isopropylphenyl）-l,l-dimethylurea, in food and environmental samples was developed. Tw...A competitive enzyme-linked immunosorbent assay （ELISA） suitable for the determination of the urea herbicide isoproturon, 3-（4-isopropylphenyl）-l,l-dimethylurea, in food and environmental samples was developed. Two haptens named 1-（3- carboxypropyl）-3-（4-isopropylphenyl）-1-methylurea （hapten 4C） and 1-（5-carboxypentyl）-3-（4-isopropylphenyl）-1- methylurea （hapten 6C） were synthesized. The haptens were coupled to bovine serum albumin （BSA） and ovalbumin （OVA）, respectively, using the N-hydroxysuccinimide reaction. The hapten 6C-BSA conjugate was used as the immunogen, with which a high-titer anti-isoproturon polyclonal antibody （pAb） was successfully obtained by immunization of New Zealand white rabbits. The hapten 4C-OVA conjugate was used as coating antigen and a method of the indirect competitive ELISA for isoproturon was established. The haptens were confirmed with TLC, IR, and 1H NMR. The conjugation molar ratios of hapten 4C to OVA and hapten 6C to BSA were 36：1 and 46：1, respectively, as calculated by a UV spectrophotometry. The highest titer of the anti-isoproturon sera determined by a non-competitive indirect ELISA procedure was 1.6 × 10^5. The optimal concentrations of the coating antigen and the dilution of the anti-isoproturon sera used in the ELISA were 0.1 mg·L^-1 and 1.0 × 10^5, respectively. The concentration of isoproturon that inhibits 50% of antibody-antigen binding （IC50） was 0.07 mg·mL^-1. The cross-reactivities of six urea herbicides including chlorbromuron, fluometuron, monolinuron were lower than 0.1%. Isoproturon is a small molecule without immune activity and active functional group for attaching to carrier protein. To produce an antibody against isoproturon with high titer and high specificity is the most important step in the development of an immunochemical method for the determination of isoproturon in food and environmental samples. The two haptens synthesized in this study have carboxyl groups and accommodate different lengths of spacer arms, and the phenyl and isopropyl groups are fully exposed. An anti-isoproturon polyclonal antibody with high titer and high specificity was successfully obtained by immunization of rabbits with the conjugate of the hapten attached to the protein carrier.展开更多
Rice ragged stunt virus（RRSV） is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein（CP） gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21（...Rice ragged stunt virus（RRSV） is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein（CP） gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21（DE3） using the pMAL-C2 X expression vector. The recombinant protein was used as the immunogen to immunize BALB/c mice. A hybridoma cell line 8A12 secreting monoclonal antibody（MAb） against RRSV was obtained by fusing mouse myeloma cells（Sp 2/0） with spleen cells from the immunized BALB/c mice. Western blot analysis showed that the MAb 8A12 can specifically react with RRSV CP. Using the MAb, an antigen-coated-plate enzyme-linked immunosorbent assay（ACP-ELISA）, a dot enzyme-linked immunosorbent assay（dot-ELISA）, and immunocapture-RT-PCR（IC-RT-PCR） assay were developed to detect RRSV. The established ACP-ELISA, dot-blot ELISA and IC-RT-PCR methods could detect RRSV in infected rice tissue crude extracts with dilutions of 1：40 960, 1：1 280 and 1：655 360（w/v, g mL-1）, respectively. The ACP-ELISA and dot-blot ELISA methods could detect RRSV in infected insect vector crude extracts with dilutions of 1：12 800 and 1：1 600（an individual planthopper μL-1）, respectively. The field survey revealed that Rice ragged stunt disease occurs on rice in Hainan, Yunnan, Guangxi, Sichuan, Guizhou, Fujian, Hunan, Jiangxi and Zhejiang in China.展开更多
The glomerulonephritis disease is characterized by inflammation of glomeruli or small blood vessels in the kidney that causes kidney diseases. The reason of glomerulonephritis disease is to deposit the anti-GBM auto a...The glomerulonephritis disease is characterized by inflammation of glomeruli or small blood vessels in the kidney that causes kidney diseases. The reason of glomerulonephritis disease is to deposit the anti-GBM auto antibody in the glomerular basement membrane. The type IV collagen is the main component of glomerular basement membrane that has α3 chain of type (IV) collagen of non-collagenous domain which contains N-terminal 7S domain, a triple helical collagenous domain and C-terminal non-collagenous glomerular domain (NC1). The amino terminal of α3 (IV) NC1 that induces the Experimental Autoimmuno Glomerulonephritis (EAG) in rat model has been identified. The recombinant rat α3 (IV) NC1 antigen has nine amino acid spans that are consistent with antibody or T cell epitope that induces in EAG. The research is carried out on the recombinant rat α3 (IV) NC1 production, purification, quantification, and characterization. The circulation of anti-GBM antibody in glomerular basement membrane can be measured by the ELISA assay. In addition, the recombinant rat antigen is secreted in HEK293 cell supernatant that is purified by Anti-FLAG M2 monoclonal IgG antibody affinity column and characterized and quantified by SDS-PAGE gel electrophoresis and Western blotting techniques.展开更多
Background Renal transplantation in sensitized candidates remains a highly significant challenge worldwide. The production of panel reactive antibody （PRA） against human leukocyte antigen （HLA） is a major risk fac...Background Renal transplantation in sensitized candidates remains a highly significant challenge worldwide. The production of panel reactive antibody （PRA） against human leukocyte antigen （HLA） is a major risk factor in presensitized recipients. The aim of this study was to evaluate the impact of HLA matching and recipients＇ PRA on two-year outcome in presensitized renal allograft recipients. Methods We determined the percentage of panel reactivity and specificity of anti-HLA immunoglobulin （Ig） G antibodies in 73 presensitized renal allograft recipients compared with 81 unsensitized recipients （control group）. HLA genotyping of both recipients and corresponding donors was performed by PCR with sequence-specific primers （PCR-SSP）. We analyzed the factors influencing the early graft outcome （two-year rejection rates and survival rates of the grafts）, including HLA mismatching, class and degree of panel reactivity, and target antigen of donors. Results Presensitized recipients had a worse two-year outcome than unsensitized recipients （P=0.019 for rejection rate, P=0.01 for survival rate）. The difference in number of HLA-mismatched alleles with either 6-antigen matching （Ag M） standard or amino acid residue matching （Res M） standard was not significant between the rejection and non-rejection groups of presensitized recipients or between the graft survival group and graft loss group. Compared with the control group, recipients with both PRA-I and PRA-II antibodies had a significantly worse two-year outcome （P=0.001 for rejection rate, P=0.002 for survival rate）. The two-year outcomes of the peak PRA 〉50% group and its subgroup, at-transplant PRA 〉50% group, were significantly worse compared with the control group （P=0.025 and P=0.001 for rejection rate, P=0.043 and P=0.024 for survival rate）. The rejection rates of the at-transplant target antigen positive group and its subgroup, HLA-I target antigen positive group, were significantly higher than the control group （P=0.001 and P=-0.001）, target antigen negative group （P=0.003 and P=0.001）, and peak target antigen positive with negative at-transplant target antigen group （P=0.024 and ,0=-0.002）. Two-year graft survival rates of the target antigen positive group and HLA-I target antigen positive group were significantly lower than the control group （P=0.012 and ,P=0.001）. The two-year outcome of target antigen unknown group was similar to that of the target antigen positive group. Presensitized recipients with pre-transplant plasmapheresis or immunoadsorption （PRA prepared group） had a better but non-significant two-year outcome than the control group. However, the PRA unprepared presensitized recipients were different to the control group （P=-0.004 for rejection rate and P=-0.005 for survival rate）. Hyperacute rejection （HR） occurred in three recipients with positive HLA-I target antigen and without mismatch according to Res M and in one case with positive PRA-II （for an unknown target antigen）. No HR occurred in eight cases with positive HLA-II target antigens. Conclusions Pre-transplant PRA preparations might improve the access of presensitized patients to renal donors. Avoiding antigen-positive donors remains a fundamental measure in preventing HR and early rejections.展开更多
Dextran coated magnetic nanocomposites were prepared. A periodate oxidation method was used to further activate the magnetic dextran, forming magnetic polyaldehyde dextran, which could be conjugated to biomolecules, a...Dextran coated magnetic nanocomposites were prepared. A periodate oxidation method was used to further activate the magnetic dextran, forming magnetic polyaldehyde dextran, which could be conjugated to biomolecules, antibodes. The magnetic labeled nano scaled bioconjugates could be well blocked with BSA and exhibit high activity by ELISA and immunochromatographic strip assay.展开更多
文摘Reports manifest a continuing need for the development of rapid and on-site (point of care) assays. Current diagnostic methods commonly used for detection of antibodies and antigens have significant limitations. Scientists at Micro Detect, Inc. have developed an innovative diagnostic device (method) that can be utilized broadly for antibody/antigen interactions including diagnostic assays in the medical, veterinary and food industries. The developed device can be utilized for the detection of antibodies against a single antigen or vice versa. It can also be tailored for specific panels that detect antigens or antibodies for diverse infectious agents, proteins, hormones, tumor markers, autoimmune markers, and allergens. Additionally, it can also be used for detection of toxins, antitoxins, nucleic acids, enzymes, drugs, etc. in both humans and animals. Specimens used in different formats of the device can be tears, saliva, whole blood, serum, plasma, urine, stool, and other bodily discharges. The good intra and inter precisions and acceptable linearity of the device support reliable use of the device. The CV of the device is 1.9% - 2.2%. Likewise, the performance of the device using 92 confirmed negative and positive specimens via a typical assay showed 100% sensitivity, 80% specificity, 96.8% efficacy, 80% positive predictive value, and 100% negative predictive value. The results of our feasibility study suggest reliable utility of a device for rapid, easy-to-use, inexpensive, and on-site (point of care) diagnostic assays. This presents a potential breakthrough in diagnostic methodologies that can be integrated into modern medicine and food industries.
基金The project was supported by the National Natural Science Foundation of China,No 3860869
文摘Merozoite surface antigens can induce protective immune responses and may becandidate antigens for malaria vaccine.Four hybridoma cell lines secreting monoclonalantibodies against Plasmodium falciparum Fcc7801/HN were produced.Antibodies fromthree of the four lines showed significant growth-inhibiting effect on P.falciparum invitro.One monoclonal antibody,known as C6,conjugated the antigen located exclusivelyon the merozoite surface and distributed evenly over the entire surface,as wasdemonstrated by immunoelectron microscopy.C6 also precipitated a single protein of Mr71000.
文摘目的建立间接竞争酶联免疫吸附测定法快速筛查药酒中双氯芬酸(diclofenac,DCF)。方法采用活性酯法和混合酸酐法分别将DCF与载体蛋白耦合,得到DCF的免疫原和检测抗原。采用DCF-牛血清白蛋白免疫BALB/c小鼠,随后用杂交瘤等技术制备抗DCF单克隆抗体(monoclon alantibody,mAb),基于DCFmAb建立了间接竞争酶联免疫吸附测定法,对该检测方法的性能(准确度、精密度和特异性)进行鉴定。结果紫外扫描结果表明DCF已成功与载体蛋白偶联;获得最优株抗DCF的杂交瘤细胞株(4B9),其IC50值为0.61ng/mL;该检测方法在药酒中的DCF平均添加回收率为85.9%,其批间变异系数(coefficient of variation,CV)(5.3%~9.7%)均大于批内CV(4.9%~9.1%),与类似物(酮洛芬、阿司匹林、吲哚美辛、布洛芬、舒林酸、萘普生、罗非昔布)没有交叉反应。结论本研究建立的间接竞争ELISA法为DCF在药酒中的残留提供了一种新的筛查手段。
基金This work was financially supported by National Natural Science Foundation of China （20447003）.
文摘A competitive enzyme-linked immunosorbent assay （ELISA） suitable for the determination of the urea herbicide isoproturon, 3-（4-isopropylphenyl）-l,l-dimethylurea, in food and environmental samples was developed. Two haptens named 1-（3- carboxypropyl）-3-（4-isopropylphenyl）-1-methylurea （hapten 4C） and 1-（5-carboxypentyl）-3-（4-isopropylphenyl）-1- methylurea （hapten 6C） were synthesized. The haptens were coupled to bovine serum albumin （BSA） and ovalbumin （OVA）, respectively, using the N-hydroxysuccinimide reaction. The hapten 6C-BSA conjugate was used as the immunogen, with which a high-titer anti-isoproturon polyclonal antibody （pAb） was successfully obtained by immunization of New Zealand white rabbits. The hapten 4C-OVA conjugate was used as coating antigen and a method of the indirect competitive ELISA for isoproturon was established. The haptens were confirmed with TLC, IR, and 1H NMR. The conjugation molar ratios of hapten 4C to OVA and hapten 6C to BSA were 36：1 and 46：1, respectively, as calculated by a UV spectrophotometry. The highest titer of the anti-isoproturon sera determined by a non-competitive indirect ELISA procedure was 1.6 × 10^5. The optimal concentrations of the coating antigen and the dilution of the anti-isoproturon sera used in the ELISA were 0.1 mg·L^-1 and 1.0 × 10^5, respectively. The concentration of isoproturon that inhibits 50% of antibody-antigen binding （IC50） was 0.07 mg·mL^-1. The cross-reactivities of six urea herbicides including chlorbromuron, fluometuron, monolinuron were lower than 0.1%. Isoproturon is a small molecule without immune activity and active functional group for attaching to carrier protein. To produce an antibody against isoproturon with high titer and high specificity is the most important step in the development of an immunochemical method for the determination of isoproturon in food and environmental samples. The two haptens synthesized in this study have carboxyl groups and accommodate different lengths of spacer arms, and the phenyl and isopropyl groups are fully exposed. An anti-isoproturon polyclonal antibody with high titer and high specificity was successfully obtained by immunization of rabbits with the conjugate of the hapten attached to the protein carrier.
基金supported by the National Basic Research Program of China(2010CB126203)the special fund for Agro-scientific Research in the Public Interest,China(201003031)+1 种基金Earmarked Funds for Modern Agro-industry Technology Research SystemZhejiang Provincial Natural Science Foundation of China(Z3090039)
文摘Rice ragged stunt virus（RRSV） is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein（CP） gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21（DE3） using the pMAL-C2 X expression vector. The recombinant protein was used as the immunogen to immunize BALB/c mice. A hybridoma cell line 8A12 secreting monoclonal antibody（MAb） against RRSV was obtained by fusing mouse myeloma cells（Sp 2/0） with spleen cells from the immunized BALB/c mice. Western blot analysis showed that the MAb 8A12 can specifically react with RRSV CP. Using the MAb, an antigen-coated-plate enzyme-linked immunosorbent assay（ACP-ELISA）, a dot enzyme-linked immunosorbent assay（dot-ELISA）, and immunocapture-RT-PCR（IC-RT-PCR） assay were developed to detect RRSV. The established ACP-ELISA, dot-blot ELISA and IC-RT-PCR methods could detect RRSV in infected rice tissue crude extracts with dilutions of 1：40 960, 1：1 280 and 1：655 360（w/v, g mL-1）, respectively. The ACP-ELISA and dot-blot ELISA methods could detect RRSV in infected insect vector crude extracts with dilutions of 1：12 800 and 1：1 600（an individual planthopper μL-1）, respectively. The field survey revealed that Rice ragged stunt disease occurs on rice in Hainan, Yunnan, Guangxi, Sichuan, Guizhou, Fujian, Hunan, Jiangxi and Zhejiang in China.
文摘The glomerulonephritis disease is characterized by inflammation of glomeruli or small blood vessels in the kidney that causes kidney diseases. The reason of glomerulonephritis disease is to deposit the anti-GBM auto antibody in the glomerular basement membrane. The type IV collagen is the main component of glomerular basement membrane that has α3 chain of type (IV) collagen of non-collagenous domain which contains N-terminal 7S domain, a triple helical collagenous domain and C-terminal non-collagenous glomerular domain (NC1). The amino terminal of α3 (IV) NC1 that induces the Experimental Autoimmuno Glomerulonephritis (EAG) in rat model has been identified. The recombinant rat α3 (IV) NC1 antigen has nine amino acid spans that are consistent with antibody or T cell epitope that induces in EAG. The research is carried out on the recombinant rat α3 (IV) NC1 production, purification, quantification, and characterization. The circulation of anti-GBM antibody in glomerular basement membrane can be measured by the ELISA assay. In addition, the recombinant rat antigen is secreted in HEK293 cell supernatant that is purified by Anti-FLAG M2 monoclonal IgG antibody affinity column and characterized and quantified by SDS-PAGE gel electrophoresis and Western blotting techniques.
文摘Background Renal transplantation in sensitized candidates remains a highly significant challenge worldwide. The production of panel reactive antibody （PRA） against human leukocyte antigen （HLA） is a major risk factor in presensitized recipients. The aim of this study was to evaluate the impact of HLA matching and recipients＇ PRA on two-year outcome in presensitized renal allograft recipients. Methods We determined the percentage of panel reactivity and specificity of anti-HLA immunoglobulin （Ig） G antibodies in 73 presensitized renal allograft recipients compared with 81 unsensitized recipients （control group）. HLA genotyping of both recipients and corresponding donors was performed by PCR with sequence-specific primers （PCR-SSP）. We analyzed the factors influencing the early graft outcome （two-year rejection rates and survival rates of the grafts）, including HLA mismatching, class and degree of panel reactivity, and target antigen of donors. Results Presensitized recipients had a worse two-year outcome than unsensitized recipients （P=0.019 for rejection rate, P=0.01 for survival rate）. The difference in number of HLA-mismatched alleles with either 6-antigen matching （Ag M） standard or amino acid residue matching （Res M） standard was not significant between the rejection and non-rejection groups of presensitized recipients or between the graft survival group and graft loss group. Compared with the control group, recipients with both PRA-I and PRA-II antibodies had a significantly worse two-year outcome （P=0.001 for rejection rate, P=0.002 for survival rate）. The two-year outcomes of the peak PRA 〉50% group and its subgroup, at-transplant PRA 〉50% group, were significantly worse compared with the control group （P=0.025 and P=0.001 for rejection rate, P=0.043 and P=0.024 for survival rate）. The rejection rates of the at-transplant target antigen positive group and its subgroup, HLA-I target antigen positive group, were significantly higher than the control group （P=0.001 and P=-0.001）, target antigen negative group （P=0.003 and P=0.001）, and peak target antigen positive with negative at-transplant target antigen group （P=0.024 and ,0=-0.002）. Two-year graft survival rates of the target antigen positive group and HLA-I target antigen positive group were significantly lower than the control group （P=0.012 and ,P=0.001）. The two-year outcome of target antigen unknown group was similar to that of the target antigen positive group. Presensitized recipients with pre-transplant plasmapheresis or immunoadsorption （PRA prepared group） had a better but non-significant two-year outcome than the control group. However, the PRA unprepared presensitized recipients were different to the control group （P=-0.004 for rejection rate and P=-0.005 for survival rate）. Hyperacute rejection （HR） occurred in three recipients with positive HLA-I target antigen and without mismatch according to Res M and in one case with positive PRA-II （for an unknown target antigen）. No HR occurred in eight cases with positive HLA-II target antigens. Conclusions Pre-transplant PRA preparations might improve the access of presensitized patients to renal donors. Avoiding antigen-positive donors remains a fundamental measure in preventing HR and early rejections.
文摘Dextran coated magnetic nanocomposites were prepared. A periodate oxidation method was used to further activate the magnetic dextran, forming magnetic polyaldehyde dextran, which could be conjugated to biomolecules, antibodes. The magnetic labeled nano scaled bioconjugates could be well blocked with BSA and exhibit high activity by ELISA and immunochromatographic strip assay.
