Postweaning multisystemic wasting syndrome (PMWS) is an important swine disease that is closely associated with porcine circovirus type 2 (PCV2). The capsid protein (Cap protein) is a major structural protein that has...Postweaning multisystemic wasting syndrome (PMWS) is an important swine disease that is closely associated with porcine circovirus type 2 (PCV2). The capsid protein (Cap protein) is a major structural protein that has at least three immunoreactive regions, and it can be a suitable candidate antigen for detecting the specific antibodies of a PCV2 infection. In the present study, an indirect enzyme-linked immunosorbent assay (TcELISA) based on a truncated soluble Cap protein produced in Escherichia coli (E.coli) was established and validated for the diagnostic PCV2 antibodies in swine. The TcELISA was validated by comparison with an indirect immunofluorescence assay (IIFA). The diagnostic sensitivity (DSN), specificity (DSP), and accuracy of the TcELISA were 88.6%, 90.7% and 89.4%, respectively. The agreement rate was 89.38% between results obtained with TcELISA and IIFA on 113 field sera. A cross-reactivity assay showed that the method was PCV2-specific by comparison with other sera of viral disease. Therefore ,the TcELISA will be helpful for the development of a reliable serology diagnostic test for large scale detection of PCV2 antibodies and for the evaluation of vaccine against PCV2 in swine.展开更多
This present study was designed to evaluate four different Blastomyces dermatitidis antibody-antigen combinations (B5896 and T-58 antibodies and B5896 and WI-R antigens) for the detection of antigen in 36 urine specim...This present study was designed to evaluate four different Blastomyces dermatitidis antibody-antigen combinations (B5896 and T-58 antibodies and B5896 and WI-R antigens) for the detection of antigen in 36 urine specimens from dogs with blastomycosis using a standard indirect ELISA (STD) and a biotin-streptavidin ELISA (B-SA). The antigen detection sensitivity values ranged from 81% (B-SA: T-58 Ab + WI-R Ag) to 100% (STD and B-SA: B5896 Ab + WI-R Ag;B5896 Ab + B5896 Ag) with the antibody-antigen combinations in the two assays. Optimal detection was evidenced when the B5896 Ab was allowed to react with the urine specimens for 30 min at 37?C and then placed in the B-SA ELISA plates containing the B5896 Ag. The greatest absorbance value obtained with this antibody-antigen com-bination was 0.903 (range of 0.596 - 0.903) as compared to the control value of 1.246. The difference between the control absorbance and the test absorbance values was 0.343 which was considerably greater than the control-test values with the other combinations. This study thus showed that the results obtained in antigen detection assays are dependent upon the antibody used to react with the urine specimens as well as the antigen used in the enzyme immunoassay.展开更多
The content of patulin in dairy products was detected by rapid ELISA assay. The pretreatment of samples was simple, with wide range of application. The standard product showed good linear relationship with the range o...The content of patulin in dairy products was detected by rapid ELISA assay. The pretreatment of samples was simple, with wide range of application. The standard product showed good linear relationship with the range of 0-5.4 μg/kg, and the linear relationship reached 0.999 3, with high sensitivity. It took shorter time, with a total time-consumption of 1 h. Moreover, it had good repeatability for analytical requirements.展开更多
Objective : Telomeric repeat amplification protocol (TRAP) is now a conventional assay for detecting telomerase activity. However, this method presents problems related to tedious quantifying, radioisotopic handing a...Objective : Telomeric repeat amplification protocol (TRAP) is now a conventional assay for detecting telomerase activity. However, this method presents problems related to tedious quantifying, radioisotopic handing and the limited number of samples to be examined. In order to alleviate these inconveniences, we have developed and evaluated a novel telomerase TRAP ELISA assay detecting human telomerase activity. Method: Telomerase TRAP ELISA assay is a system based on the combination of PCR ELISA with TRAP. Comparing with the conventional TRAP assay, we detected telomerase activity in 293 cell and negative controls (RNase pretreated or heat treated). Result : Telomerase activity in 293 cell is positive. The OD value of serial extracts from 10、10 2、10 3 and 10 4 cells assayed by telomerase PCR ELISA depended on the number of 293 cells in assay. RNase pretreated or heat treated control was negative. Telomerase TRAP ELISA detection yields results within one day and is handled without radioisotopes. Conclusion : Telomerase TRAP ELISA assay is non radioisotopic, fast and quantitative method for detecting human telomerase activity.展开更多
In this study, various factors of ELISA for detection of sulfamethazine residues were explored, the coating antigen was diluted to 1：400, the best coating condition was at 4℃ overnight, the working concentration of ...In this study, various factors of ELISA for detection of sulfamethazine residues were explored, the coating antigen was diluted to 1：400, the best coating condition was at 4℃ overnight, the working concentration of HRP-IgG enzyme conjugate was 1 ： 7 000. The pre-incubation time and incubation time was 30 min and 120 min, respectively, the substrate solution working time was 20 min. Two moL · L^-1 H2SO4 was used to stop the reaction and checked. A standard curve of direct competitive ELISA had been established to detect the sulfamethazine residues in milk. The detection limit of this method was 1.97 ng · mL^-1. The mean concentration of sulfamethazine required to inhibit 30% antibody was 7.1 ng · mL^-1. The linear range of the detection was 5-200 ng · mL^-1. The recovery ratio was between 73.20% and 91.16%. The CV% of within array and between arrays was less than 10%.展开更多
基金supported by a project from National Key Technology R&D Program in the 11th Fiveyear Plan of China (2006BAD06A12)
文摘Postweaning multisystemic wasting syndrome (PMWS) is an important swine disease that is closely associated with porcine circovirus type 2 (PCV2). The capsid protein (Cap protein) is a major structural protein that has at least three immunoreactive regions, and it can be a suitable candidate antigen for detecting the specific antibodies of a PCV2 infection. In the present study, an indirect enzyme-linked immunosorbent assay (TcELISA) based on a truncated soluble Cap protein produced in Escherichia coli (E.coli) was established and validated for the diagnostic PCV2 antibodies in swine. The TcELISA was validated by comparison with an indirect immunofluorescence assay (IIFA). The diagnostic sensitivity (DSN), specificity (DSP), and accuracy of the TcELISA were 88.6%, 90.7% and 89.4%, respectively. The agreement rate was 89.38% between results obtained with TcELISA and IIFA on 113 field sera. A cross-reactivity assay showed that the method was PCV2-specific by comparison with other sera of viral disease. Therefore ,the TcELISA will be helpful for the development of a reliable serology diagnostic test for large scale detection of PCV2 antibodies and for the evaluation of vaccine against PCV2 in swine.
文摘This present study was designed to evaluate four different Blastomyces dermatitidis antibody-antigen combinations (B5896 and T-58 antibodies and B5896 and WI-R antigens) for the detection of antigen in 36 urine specimens from dogs with blastomycosis using a standard indirect ELISA (STD) and a biotin-streptavidin ELISA (B-SA). The antigen detection sensitivity values ranged from 81% (B-SA: T-58 Ab + WI-R Ag) to 100% (STD and B-SA: B5896 Ab + WI-R Ag;B5896 Ab + B5896 Ag) with the antibody-antigen combinations in the two assays. Optimal detection was evidenced when the B5896 Ab was allowed to react with the urine specimens for 30 min at 37?C and then placed in the B-SA ELISA plates containing the B5896 Ag. The greatest absorbance value obtained with this antibody-antigen com-bination was 0.903 (range of 0.596 - 0.903) as compared to the control value of 1.246. The difference between the control absorbance and the test absorbance values was 0.343 which was considerably greater than the control-test values with the other combinations. This study thus showed that the results obtained in antigen detection assays are dependent upon the antibody used to react with the urine specimens as well as the antigen used in the enzyme immunoassay.
文摘The content of patulin in dairy products was detected by rapid ELISA assay. The pretreatment of samples was simple, with wide range of application. The standard product showed good linear relationship with the range of 0-5.4 μg/kg, and the linear relationship reached 0.999 3, with high sensitivity. It took shorter time, with a total time-consumption of 1 h. Moreover, it had good repeatability for analytical requirements.
文摘Objective : Telomeric repeat amplification protocol (TRAP) is now a conventional assay for detecting telomerase activity. However, this method presents problems related to tedious quantifying, radioisotopic handing and the limited number of samples to be examined. In order to alleviate these inconveniences, we have developed and evaluated a novel telomerase TRAP ELISA assay detecting human telomerase activity. Method: Telomerase TRAP ELISA assay is a system based on the combination of PCR ELISA with TRAP. Comparing with the conventional TRAP assay, we detected telomerase activity in 293 cell and negative controls (RNase pretreated or heat treated). Result : Telomerase activity in 293 cell is positive. The OD value of serial extracts from 10、10 2、10 3 and 10 4 cells assayed by telomerase PCR ELISA depended on the number of 293 cells in assay. RNase pretreated or heat treated control was negative. Telomerase TRAP ELISA detection yields results within one day and is handled without radioisotopes. Conclusion : Telomerase TRAP ELISA assay is non radioisotopic, fast and quantitative method for detecting human telomerase activity.
基金Supported by Key Items of National Technology Research Project(2002BA518A06)Heilongjiang Provincial Science and Technology Tackle Key Problem Project(10541021)Harbin Technical Fund(2003AA6CN179)
文摘In this study, various factors of ELISA for detection of sulfamethazine residues were explored, the coating antigen was diluted to 1：400, the best coating condition was at 4℃ overnight, the working concentration of HRP-IgG enzyme conjugate was 1 ： 7 000. The pre-incubation time and incubation time was 30 min and 120 min, respectively, the substrate solution working time was 20 min. Two moL · L^-1 H2SO4 was used to stop the reaction and checked. A standard curve of direct competitive ELISA had been established to detect the sulfamethazine residues in milk. The detection limit of this method was 1.97 ng · mL^-1. The mean concentration of sulfamethazine required to inhibit 30% antibody was 7.1 ng · mL^-1. The linear range of the detection was 5-200 ng · mL^-1. The recovery ratio was between 73.20% and 91.16%. The CV% of within array and between arrays was less than 10%.
