Background:This study was planned to assess the accuracy and comparability of two commercially available,laboratory-based SARS-CoV-2(severe acute respiratory syndrome)antigen(Ag)immunoassays.Methods:We studied a cohor...Background:This study was planned to assess the accuracy and comparability of two commercially available,laboratory-based SARS-CoV-2(severe acute respiratory syndrome)antigen(Ag)immunoassays.Methods:We studied a cohort of subjects with acute SARS-CoV-2 infection,from whom a nasopharyngeal swab was taken and tested with a molecular assay(Altona Diagnostics RealStar SARS-CoV-2 RT-PCR Kit)and two laboratory-based,fully automated SARS-CoV-2 Ag immunoassays(Fujirebio Lumipulse G SARS-CoV-2 Ag and Roche Elecsys SARS-CoV-2 Ag).Results:The final population consisted in 93 subjects testing positive for SARS-CoV-2 RNA,34 with cycle threshold(Ct)values<29.5.The results of the two SARS-CoV-2 Ag immunoassays were significantly intercorrelated(r=0.77;P<0.001)in the entire cohort,though such correlation considerably improved in patients with high viral load(cycle threshold values<29.5:r=0.96;P<0.001).The accuracy for identifying samples with high viral load was excellent for both Lumipulse G SARS-CoV-2 Ag(AUC,0.99;P<0.001)and Elecsys SARS-CoV-2 Ag(AUC,0.99;P<0.001),with best cut-offs of 2.03 ng/mL for Lumipulse G SARS-CoV-2 Ag(1.00 sensitivity and 0.88 specificity)and 0.70 COI for Elecsys SARS-CoV-2 Ag(1.00 sensitivity and 0.80 specificity),respectively.Conclusion:The results of this study provide valuable support to usability of fully-automated,rapid,high throughput and accurate SARS-CoV-2 Ag immunoassays for complementing molecular assays.展开更多
A fluorescence polarization immunoassay (FPIA) was developed for the analysis ofaflatoxins (AFs) using an anti-aflatoxin B1 (AFB1) monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed...A fluorescence polarization immunoassay (FPIA) was developed for the analysis ofaflatoxins (AFs) using an anti-aflatoxin B1 (AFB1) monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed an IC50 value of 23.33 ng/mL with a limit of detection of 13.12 ng/mL for AFB1. The cross-reactivities of AFB1, AFB2, AFG1, AFG2, AFM1, and AFM2 with the antibody were 100%, 65.7%, 143%, 23.5%, 111.4%, and 2%, respectively. The group-specificity of anti-AFB1mAb indicated that the FPIA could potentially be used in a screening method for the detection of total AFs, albeit not AFG2 and AFM2. The total time required for analyzing 96 samples in one microplate was less than 5 rain. This study demonstrates the potential usefulness of the FPIA as a rapid and simple technique for monitoring AFs.展开更多
Glypican-3 (GPC3) is reported as a great promising tumor marker for hepatocellular carcinoma (HCC) diagnosis. Highly sensitive and accurate analysis of serum GPC3 (sGPC3), in combination with or instead of tradi...Glypican-3 (GPC3) is reported as a great promising tumor marker for hepatocellular carcinoma (HCC) diagnosis. Highly sensitive and accurate analysis of serum GPC3 (sGPC3), in combination with or instead of traditional HCC marker alpha-fetoprotein (AFP), is essential for early diagnosis of I-ICC. Biomaterial-functionalized magnetic particles have been utilized as solid supports with good biological compatibility for sensitive immunoassay. Here, the magnetic nanoparticles (MnPs) and magnetic microparticles (MmPs) with carboxyl groups were further modified with streptavidin, and applied for the development of chemiluminescence enzyme immunoassay (CLEIA). After comparing between MnPs- and MmPs-based CLEIA, MnPs-based CLEIA was proved to be a better method with less assay time, greater sensitivity, better linearity and longer chemiluminescence platform. MnPs-based CLEIA was applied for detection of sGPC3 in normal liver, hepatocirrhosis, secondary liver cancer and HCC serum samples. The results indicated that sGPC3 was effective in diagnosis of HCC with high performance.展开更多
Lateral flow immunoassay(LFIA) is a widely used express method and offers advantages such as a short analysis time, simplicity of testing and result evaluation.However, an LFIA based on gold nanospheres lacks the desi...Lateral flow immunoassay(LFIA) is a widely used express method and offers advantages such as a short analysis time, simplicity of testing and result evaluation.However, an LFIA based on gold nanospheres lacks the desired sensitivity, thereby limiting its wide applications.In this study, spherical nanogold labels along with new types of nanogold labels such as gold nanopopcorns and nanostars were prepared, characterized, and applied for LFIA of model protein antigen procalcitonin. It was found that the label with a structure close to spherical provided more uniform distribution of specific antibodies on its surface, indicative of its suitability for this type of analysis.LFIA using gold nanopopcorns as a label allowed procalcitonin detection over a linear range of 0.5–10 ng mL^(-1) with the limit of detection of 0.1 ng mL^(-1), which was fivefold higher than the sensitivity of the assay with gold nanospheres. Another approach to improve the sensitivity of the assay included the silver enhancement method,which was used to compare the amplification of LFIA for procalcitonin detection. The sensitivity of procalcitonin determination by this method was 10 times better the sensitivity of the conventional LFIA with gold nanosphere as a label. The proposed approach of LFIA based on gold nanopopcorns improved the detection sensitivity without additional steps and prevented the increased consumption of specific reagents(antibodies).展开更多
A chemiluminescence enzyme immunoassay based on magnetic microparticles (MmPs-CLEIA) was developed to evaluate serum a-fetoprotein (AFP) in parallel with traditional colorimetric enzyme-linked immunosorbent assay (ELI...A chemiluminescence enzyme immunoassay based on magnetic microparticles (MmPs-CLEIA) was developed to evaluate serum a-fetoprotein (AFP) in parallel with traditional colorimetric enzyme-linked immunosorbent assay (ELISA).A systematic comparison between the MmPs-CLEIA and colorimetric ELISA concluded that the MPs-CLEIA exhibited fewer dosages of immunoreagents,less total assay time,and better linearity,recovery,precision,sensitivity and validity.AFP was detected in forty human serum samples by the proposed MPs-CLEIA and ELISA,and the results were compared with commercial electrochemiluminescence immunoassay (ECLIA) kit.The correlation coefficient between MPs-CLEIA and ELISA was obtained with R 2 0.6703;however,the correlation between MPs-CLEIA and ECLIA (R 2 0.9582) was obviously better than that between colorimetric ELISA and ECLIA (R 2 0.6866).展开更多
The detection of chemical contaminants is critical to ensure dairy safety. These contaminants include veterinary medicines, antibiotics, pesticides, heavy metals, mycotoxins, and persistent organic pollutants (POPs)...The detection of chemical contaminants is critical to ensure dairy safety. These contaminants include veterinary medicines, antibiotics, pesticides, heavy metals, mycotoxins, and persistent organic pollutants (POPs). Immunoassays have recently been used to detect contaminants in milk because of their simple operation, high speed, and low cost. This article describes the latest developments in the most important component of immunoassays--antibodies, and then reviews the four major substrates used for immunoassays (i.e., microplates, membranes, gels, and chips) as well as their use in the detection of milk contaminants. The paper concludes with prospects for further aDDlications of these immunoassavs.展开更多
Preparation and characterization of the hapten-protein conjugates are fundamental to developing environmental immunoassays. As a hapten, 1-pyrenebutyric acid(PBA) was conjugated to the carrier protein of bovine seru...Preparation and characterization of the hapten-protein conjugates are fundamental to developing environmental immunoassays. As a hapten, 1-pyrenebutyric acid(PBA) was conjugated to the carrier protein of bovine serum albumin(BSA) or ovalbumin(OVA) by active ester method. Infrared spectra(IR) showed that PBA-BSA and PBA-OVA conjugates were successfully prepared. The number of the haptens conjugated to the carrier protein was determined by ultraviolet spectra(UV) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF-MS). The calculated average binding ratios of PBA/BSA and PBA/OVA were 18:1 and 10:1 by UV, and 31:1 and 22:1 by MALDI-TOF-MS, respectively. Although there was a discrepancy between the results determined by the two methods, both of them were useful for the characterization of the hapten-protein conjugates. The antibody was produced against the antigen of PBA-BSA, and the affinity was tested by the double agar diffusion method The conjugates and the antibody could be used for developing a sensitive and selective immunoassay of polycyclic aromatic hydrocarbons(PAHs).展开更多
A new hapten, aldicarb oxime succinic ester (AOSE), was synthesized for immunoassay of aldicarb. It was conjugated to proteins by active ester method. Polyclonal antibody was raised against AOSE-BSA (bovine serum a...A new hapten, aldicarb oxime succinic ester (AOSE), was synthesized for immunoassay of aldicarb. It was conjugated to proteins by active ester method. Polyclonal antibody was raised against AOSE-BSA (bovine serum albumin) conjugate. Enzyme-linked immunosorbent assays (ELISAs) showed that this antiserum had high affinity to aldicarb and can be used for sensitive and selective immunoassay of aldicarb.展开更多
A strip reader based lateral flow immunoassay (LFIA) was established for the rapid and quantitative detection of ractopamine (RAC) in swine urine. The ratio of the optical densities (ODs) of the test line (AT)...A strip reader based lateral flow immunoassay (LFIA) was established for the rapid and quantitative detection of ractopamine (RAC) in swine urine. The ratio of the optical densities (ODs) of the test line (AT) to that of the control line (Ac) was used to effectively minimize interference among strips and sample variations. The linear range for the quantitative detection of RAC was 0.2 ng/mL to 3.5 ng/mL with a median inhibitory concentration (IC50) of 0.59+0.06 ng/mL. The limit of detection (LOD) of the LFIA was 0.13 ng/mL. The intra-assay recovery rates were 92.97%, 97.25%, and 107.41%, whereas the inter-assay rates were 80.07%, 108.17%, and 93.7%, respectively.展开更多
Immunoassays greatly contribute to veterinary drug residue analysis. However, there are few reports on detecting neomycin residues by immunoassay. Here, a rapid and sensitive chemiluminescent enzyme immunoassay (CLIE...Immunoassays greatly contribute to veterinary drug residue analysis. However, there are few reports on detecting neomycin residues by immunoassay. Here, a rapid and sensitive chemiluminescent enzyme immunoassay (CLIEA) was successfully developed for neomycin residue analysis. CLIEA demonstrated good cross-reactivity for neomycin, and the IC50 value was 2.4 ng/mL in buffer.展开更多
The feasibility and the clinical value of the enzyme-multiplied immunoassay technique (EMIT) monitoring of blood concentrations of cyclosporine A (CsA) in patients treated with CsA were investigated after kidney t...The feasibility and the clinical value of the enzyme-multiplied immunoassay technique (EMIT) monitoring of blood concentrations of cyclosporine A (CsA) in patients treated with CsA were investigated after kidney transplantation. The validation method was performed to the EMIT determination of CsA blood concentration, the CsA whole blood trough concentrations (Co) of patients in different time periods after renal transplantation were monitored, and combined with the clinical complications, the statistical results were analyzed and compared. EMIT was precise, accurate and stable, also with a high quality control. The mean postoperative blood concentration of CsA was as follows: 〈1 month, (281.4± 57.9)ng/mL; 2 - 3 months, (264.5 ± 41.2) ng/mL; 4 - 5 months, (236.4 ± 38.9) ng/mL; 6 - 12 months, (206.5± 32.6)ng/mL; 〉12 months, (185.6± 28.1)ng/mL. The toxic reaction rate of CsA blood concentration within the recommended therapeutic concentration was 14.1%, significantly lower than that of the none-recommended dose group (37.2%) (P〈0.05); the transplantation rejection rate was 4.4%, significantly lower than that of the none- recommended dose group (22.5%) (P〈0.05). Using EMIT to monitor the blood concentration of CsA as the routine laboratory method is feasible, and is able to reduce the CsA toxicity and rejection significantly, leading to achieving the desired therapeutic effect.展开更多
Mycotoxins are secondary metabolites produced by fungus.Many mycotoxin species are highly toxic and are frequently found in cereals and feedstuffs.So,powerful detection methods are vital and effective ways to prevent ...Mycotoxins are secondary metabolites produced by fungus.Many mycotoxin species are highly toxic and are frequently found in cereals and feedstuffs.So,powerful detection methods are vital and effective ways to prevent feed contamination.Traditional detection methods can no longer meet the needs of massive,real-time,simple,and fast mycotoxin monitoring.Rapid detection methods based on advanced material and sensor technology are the future trend.In this review,we highlight recent progress of mycotoxin rapid detection strategies in feedstuffs and foods,especially for simultaneous multiplex mycotoxin determination.Immunoassays,biosensors,and the prominent roles of nanomaterials are introduced.The principles of different types of recognition and signal transduction are explained,and the merits and pitfalls of these methods are compared.Furthermore,limitations and challenges of existing rapid sensing strategies and perspectives of future research are discussed.展开更多
Capillary electrophoretic immunoassay with laser-induced fluorescence detection for recombinant human interferon-gamma (IFN-g) was established. The limits of detection for three forms of IFN-g are 6.9 ng/L, 5.7 ng/L ...Capillary electrophoretic immunoassay with laser-induced fluorescence detection for recombinant human interferon-gamma (IFN-g) was established. The limits of detection for three forms of IFN-g are 6.9 ng/L, 5.7 ng/L and 5.0 ng/L, respectively.展开更多
AIM: To evaluate cortisolemia by using conventional electrochemiluminescence immunoassay(ECLIA) method compared to liquid chromatography-tandem mass spectrometry(LC-MS/MS) method in active ulcerative colitis(UC) patie...AIM: To evaluate cortisolemia by using conventional electrochemiluminescence immunoassay(ECLIA) method compared to liquid chromatography-tandem mass spectrometry(LC-MS/MS) method in active ulcerative colitis(UC) patients treated with oral prednisone(PD). METHODS: Twenty patients(12 males) with acute relapse of UC started oral PD at a dose of 40 mg once a day, tapered of 10 mg every 2 wk. When a stable 2-wk daily dose of 30 mg was reached, blood samples for cortisol levels' measurement were drawn in the morning in fasting conditions to determine circulating cortisol by LC-MS/MS and ECLIA assay. RESULTS: Median interquartile range cortisolemia with ECLIA and LC-MS/MS method was 54.1(185.8) nmol/L and 32.1(124.0) nmol/L, respectively(P < 0.001). The within-patient median differences between the two methods was 23.2(40.6) nmol/L, with higher cortisol levels for the ECLIA method. The estimated geomet-ric mean ratio between methods was 1.85(95%CI: 2.39-1.43) considering all data or 1.58(95%CI: 2.30-1.09) considering only data above the limit of quantification(n = 12). The 95%CIs of the geometric mean ratio between methods confirm a statistically significant difference.CONCLUSION: Blood cortisol levels detected with ECLIA method seems to be higher than the ones measured by LC-MS/MS, indicating a possible overestimation of them in patients treated with PD. Therefore, the cortisol suppression in patients under treatment with oral PD should not be measured using ECLIA method.展开更多
Aldosterone quantification helps evaluate the rennin-angiotensin-aldosterone system. The new bead-based mul-tiplex platform has not been applied in aldosterone detection to achieve simultaneous measurements of multipl...Aldosterone quantification helps evaluate the rennin-angiotensin-aldosterone system. The new bead-based mul-tiplex platform has not been applied in aldosterone detection to achieve simultaneous measurements of multiple hormones. A new sensitive competitive bead immunoassay based on Luminex technology for detecting aldoster-one in small sample volumes was developed using two-antibody coupled beads and biotinylated aldosterone as tracer in combination with an extraction step. The assay was validated in human and mouse samples and exhibited a linear working range from 10 to 1,000 pg/mL. The assay was reproducible and precise with intra-assay coeffi-cient of variations (CVs) from 6.0% to 11.2%, inter-assay CVs from 8.0% to 13.0% and good recovery [(90-110)%] and linearity [(89-107)%]. Excellent correlation was found between this new assay and the reference method (r = 0.96, P 0.000,1). The successful establishment of this assay provides high possibility for carrying out bead-based multiplex assay measuring aldosterone and other parameters simultaneously in one 50 μL sample so that the efficiency can be improved and precious samples can be saved.展开更多
An electrochemical method for detection of cortisol based on capillary electrophoretic enzyme immunoassay has been developed. A limit of detection of 1.7?0-9 mol/L was obtained.
A Capillary electrophortic enzyme linked immunoassay with electrochemical detection (CE-EIA-ED) has been developed. The method can be used to determine thyroxine with a limit of 3.8×10-9 mol/L.
BACKGROUND Current diagnosis of hepatitis C virus(HCV)infection requires two sequential steps:testing for anti-HCV followed by HCV RNA PCR to confirm viremia.We have developed a highly sensitive and specific HCV-antig...BACKGROUND Current diagnosis of hepatitis C virus(HCV)infection requires two sequential steps:testing for anti-HCV followed by HCV RNA PCR to confirm viremia.We have developed a highly sensitive and specific HCV-antigens enzyme immunoassay(HCV-Ags EIA)for one-step diagnosis of viremic HCV infection.AIM To assess the clinical application of the HCV-Ags EIA in one-step diagnosis of viremic HCV infection in human immunodeficiency virus(HIV)-coinfected individuals.METHODS The study blindly tested HCV-Ags EIA for its performance in one-step diagnosing viremic HCV infection in 147 sera:10 without HCV or HIV infection;54 with viremic HCV monoinfection;38 with viremic HCV/HIV coinfection;and 45 with viremic HCV and non-viremic HIV coinfection.RESULTS Upon decoding,it was 100%accordance of HCV-Ags EIA to HCV infection status by HCV RNA PCR test.In five sera with HCV infection,HCV RNA was as low as 50-59 IU/mL,and four out of five tested positive for HCV-Ags EIA.Likewise,it was also 100%accordance of HCV-Ags EIA to HCV infection status by HCV RNA PCR in 83 sera with HCV and HIV coinfection,regardless if HIV infection was active or not.CONCLUSION The modified HCV-Ags EIA has a lower detection limit equivalent to serum HCV RNA levels of approximately 100 IU/mL.It is highly sensitive and specific in the setting of HIV coinfection,regardless of HIV infection status and CD4 count.These data support the clinical application of the HCV-Ags EIA in one-step diagnosis of HCV infection in HIV-infected individuals.展开更多
We describe for the first time the synthesis and the optimal conditions for protein labeling with a new fluorescent probe,5-chlorosulfoyl-2-thenoyltrifluoroacetone(CTTA),whicb forms a highly fluorescent conplex with E...We describe for the first time the synthesis and the optimal conditions for protein labeling with a new fluorescent probe,5-chlorosulfoyl-2-thenoyltrifluoroacetone(CTTA),whicb forms a highly fluorescent conplex with Eu^(3+) when conjugated to protein.The labeled proteins were characterized by absorbance and fluorescence measurements and the effect of labeling on the biological activity of sone proteins was also studied.It is shown that the new label is suitable for applications in time-resolved fluoroimmunoassay.展开更多
文摘Background:This study was planned to assess the accuracy and comparability of two commercially available,laboratory-based SARS-CoV-2(severe acute respiratory syndrome)antigen(Ag)immunoassays.Methods:We studied a cohort of subjects with acute SARS-CoV-2 infection,from whom a nasopharyngeal swab was taken and tested with a molecular assay(Altona Diagnostics RealStar SARS-CoV-2 RT-PCR Kit)and two laboratory-based,fully automated SARS-CoV-2 Ag immunoassays(Fujirebio Lumipulse G SARS-CoV-2 Ag and Roche Elecsys SARS-CoV-2 Ag).Results:The final population consisted in 93 subjects testing positive for SARS-CoV-2 RNA,34 with cycle threshold(Ct)values<29.5.The results of the two SARS-CoV-2 Ag immunoassays were significantly intercorrelated(r=0.77;P<0.001)in the entire cohort,though such correlation considerably improved in patients with high viral load(cycle threshold values<29.5:r=0.96;P<0.001).The accuracy for identifying samples with high viral load was excellent for both Lumipulse G SARS-CoV-2 Ag(AUC,0.99;P<0.001)and Elecsys SARS-CoV-2 Ag(AUC,0.99;P<0.001),with best cut-offs of 2.03 ng/mL for Lumipulse G SARS-CoV-2 Ag(1.00 sensitivity and 0.88 specificity)and 0.70 COI for Elecsys SARS-CoV-2 Ag(1.00 sensitivity and 0.80 specificity),respectively.Conclusion:The results of this study provide valuable support to usability of fully-automated,rapid,high throughput and accurate SARS-CoV-2 Ag immunoassays for complementing molecular assays.
基金supported by grants from the International Science&Technology Cooperation Program of China(2009DFA32330)the Special Fund for Agro-scientific Research in the Public Interest(No.201203040)
文摘A fluorescence polarization immunoassay (FPIA) was developed for the analysis ofaflatoxins (AFs) using an anti-aflatoxin B1 (AFB1) monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed an IC50 value of 23.33 ng/mL with a limit of detection of 13.12 ng/mL for AFB1. The cross-reactivities of AFB1, AFB2, AFG1, AFG2, AFM1, and AFM2 with the antibody were 100%, 65.7%, 143%, 23.5%, 111.4%, and 2%, respectively. The group-specificity of anti-AFB1mAb indicated that the FPIA could potentially be used in a screening method for the detection of total AFs, albeit not AFG2 and AFM2. The total time required for analyzing 96 samples in one microplate was less than 5 rain. This study demonstrates the potential usefulness of the FPIA as a rapid and simple technique for monitoring AFs.
基金supported by the National Basic Research Program of China (973 Program,No.2007CB714507)the National Natural Science Foundation of China (No.90813015)
文摘Glypican-3 (GPC3) is reported as a great promising tumor marker for hepatocellular carcinoma (HCC) diagnosis. Highly sensitive and accurate analysis of serum GPC3 (sGPC3), in combination with or instead of traditional HCC marker alpha-fetoprotein (AFP), is essential for early diagnosis of I-ICC. Biomaterial-functionalized magnetic particles have been utilized as solid supports with good biological compatibility for sensitive immunoassay. Here, the magnetic nanoparticles (MnPs) and magnetic microparticles (MmPs) with carboxyl groups were further modified with streptavidin, and applied for the development of chemiluminescence enzyme immunoassay (CLEIA). After comparing between MnPs- and MmPs-based CLEIA, MnPs-based CLEIA was proved to be a better method with less assay time, greater sensitivity, better linearity and longer chemiluminescence platform. MnPs-based CLEIA was applied for detection of sGPC3 in normal liver, hepatocirrhosis, secondary liver cancer and HCC serum samples. The results indicated that sGPC3 was effective in diagnosis of HCC with high performance.
基金financially supported by the Ministry of Education and Science of the Russian Federation in the framework of increase Competitiveness Program of NUST ‘‘MISIS’’, implemented by a governmental decree dated 16th of March 2013, No. 211part of state assignment Organization of scientific researches (Project No. 16.6548.2017/BY)
文摘Lateral flow immunoassay(LFIA) is a widely used express method and offers advantages such as a short analysis time, simplicity of testing and result evaluation.However, an LFIA based on gold nanospheres lacks the desired sensitivity, thereby limiting its wide applications.In this study, spherical nanogold labels along with new types of nanogold labels such as gold nanopopcorns and nanostars were prepared, characterized, and applied for LFIA of model protein antigen procalcitonin. It was found that the label with a structure close to spherical provided more uniform distribution of specific antibodies on its surface, indicative of its suitability for this type of analysis.LFIA using gold nanopopcorns as a label allowed procalcitonin detection over a linear range of 0.5–10 ng mL^(-1) with the limit of detection of 0.1 ng mL^(-1), which was fivefold higher than the sensitivity of the assay with gold nanospheres. Another approach to improve the sensitivity of the assay included the silver enhancement method,which was used to compare the amplification of LFIA for procalcitonin detection. The sensitivity of procalcitonin determination by this method was 10 times better the sensitivity of the conventional LFIA with gold nanosphere as a label. The proposed approach of LFIA based on gold nanopopcorns improved the detection sensitivity without additional steps and prevented the increased consumption of specific reagents(antibodies).
基金supported by the National Basic Research Program of China (973 Program,no. 2007CB714507)National Nature Science Foundation of China (no. 90813015)
文摘A chemiluminescence enzyme immunoassay based on magnetic microparticles (MmPs-CLEIA) was developed to evaluate serum a-fetoprotein (AFP) in parallel with traditional colorimetric enzyme-linked immunosorbent assay (ELISA).A systematic comparison between the MmPs-CLEIA and colorimetric ELISA concluded that the MPs-CLEIA exhibited fewer dosages of immunoreagents,less total assay time,and better linearity,recovery,precision,sensitivity and validity.AFP was detected in forty human serum samples by the proposed MPs-CLEIA and ELISA,and the results were compared with commercial electrochemiluminescence immunoassay (ECLIA) kit.The correlation coefficient between MPs-CLEIA and ELISA was obtained with R 2 0.6703;however,the correlation between MPs-CLEIA and ECLIA (R 2 0.9582) was obviously better than that between colorimetric ELISA and ECLIA (R 2 0.6866).
基金financially supported by the Beijing Dairy Industry Innovation TeamFeed Quality and Safety Control Innovation Team of Chinese Academy of Agricultural Sciences
文摘The detection of chemical contaminants is critical to ensure dairy safety. These contaminants include veterinary medicines, antibiotics, pesticides, heavy metals, mycotoxins, and persistent organic pollutants (POPs). Immunoassays have recently been used to detect contaminants in milk because of their simple operation, high speed, and low cost. This article describes the latest developments in the most important component of immunoassays--antibodies, and then reviews the four major substrates used for immunoassays (i.e., microplates, membranes, gels, and chips) as well as their use in the detection of milk contaminants. The paper concludes with prospects for further aDDlications of these immunoassavs.
基金Supported by National High-Tech Research and Development Program of China(No.2002AA649180)PhD Programs Foundation of Ministry of Education of China(No.20010055005)
文摘Preparation and characterization of the hapten-protein conjugates are fundamental to developing environmental immunoassays. As a hapten, 1-pyrenebutyric acid(PBA) was conjugated to the carrier protein of bovine serum albumin(BSA) or ovalbumin(OVA) by active ester method. Infrared spectra(IR) showed that PBA-BSA and PBA-OVA conjugates were successfully prepared. The number of the haptens conjugated to the carrier protein was determined by ultraviolet spectra(UV) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF-MS). The calculated average binding ratios of PBA/BSA and PBA/OVA were 18:1 and 10:1 by UV, and 31:1 and 22:1 by MALDI-TOF-MS, respectively. Although there was a discrepancy between the results determined by the two methods, both of them were useful for the characterization of the hapten-protein conjugates. The antibody was produced against the antigen of PBA-BSA, and the affinity was tested by the double agar diffusion method The conjugates and the antibody could be used for developing a sensitive and selective immunoassay of polycyclic aromatic hydrocarbons(PAHs).
文摘A new hapten, aldicarb oxime succinic ester (AOSE), was synthesized for immunoassay of aldicarb. It was conjugated to proteins by active ester method. Polyclonal antibody was raised against AOSE-BSA (bovine serum albumin) conjugate. Enzyme-linked immunosorbent assays (ELISAs) showed that this antiserum had high affinity to aldicarb and can be used for sensitive and selective immunoassay of aldicarb.
基金supported by the national science and technology support program in the 12th Five Year Plan(2011BAK10B04 and 2011BAK10B01)the national natural science foundation of China(Grant No.31160323)the research program of the state key laboratory of food science and technology,Nanchang University(SKLF-ZZB-201306)
文摘A strip reader based lateral flow immunoassay (LFIA) was established for the rapid and quantitative detection of ractopamine (RAC) in swine urine. The ratio of the optical densities (ODs) of the test line (AT) to that of the control line (Ac) was used to effectively minimize interference among strips and sample variations. The linear range for the quantitative detection of RAC was 0.2 ng/mL to 3.5 ng/mL with a median inhibitory concentration (IC50) of 0.59+0.06 ng/mL. The limit of detection (LOD) of the LFIA was 0.13 ng/mL. The intra-assay recovery rates were 92.97%, 97.25%, and 107.41%, whereas the inter-assay rates were 80.07%, 108.17%, and 93.7%, respectively.
基金supported by the project for talent training and development of the China National Center for Food Safety Risk Assessment(523 plan)Natural Science Foundation of Guangdong Province(No.2014A030310289 and No.2016A020210055)+1 种基金Natural Science Foundation of SZU(No.201576)National Natural Science Foundation of China(No.21107104)
文摘Immunoassays greatly contribute to veterinary drug residue analysis. However, there are few reports on detecting neomycin residues by immunoassay. Here, a rapid and sensitive chemiluminescent enzyme immunoassay (CLIEA) was successfully developed for neomycin residue analysis. CLIEA demonstrated good cross-reactivity for neomycin, and the IC50 value was 2.4 ng/mL in buffer.
基金supported by the Project 973 Monitoring of the Immune Status and Rejection After Organ Transplantation"(2009CB522400)the National Natural Science Foundation of China(No.30972947)
文摘The feasibility and the clinical value of the enzyme-multiplied immunoassay technique (EMIT) monitoring of blood concentrations of cyclosporine A (CsA) in patients treated with CsA were investigated after kidney transplantation. The validation method was performed to the EMIT determination of CsA blood concentration, the CsA whole blood trough concentrations (Co) of patients in different time periods after renal transplantation were monitored, and combined with the clinical complications, the statistical results were analyzed and compared. EMIT was precise, accurate and stable, also with a high quality control. The mean postoperative blood concentration of CsA was as follows: 〈1 month, (281.4± 57.9)ng/mL; 2 - 3 months, (264.5 ± 41.2) ng/mL; 4 - 5 months, (236.4 ± 38.9) ng/mL; 6 - 12 months, (206.5± 32.6)ng/mL; 〉12 months, (185.6± 28.1)ng/mL. The toxic reaction rate of CsA blood concentration within the recommended therapeutic concentration was 14.1%, significantly lower than that of the none-recommended dose group (37.2%) (P〈0.05); the transplantation rejection rate was 4.4%, significantly lower than that of the none- recommended dose group (22.5%) (P〈0.05). Using EMIT to monitor the blood concentration of CsA as the routine laboratory method is feasible, and is able to reduce the CsA toxicity and rejection significantly, leading to achieving the desired therapeutic effect.
基金The financial support from the National Key Research and Development Program of China(2017YFC1600300).
文摘Mycotoxins are secondary metabolites produced by fungus.Many mycotoxin species are highly toxic and are frequently found in cereals and feedstuffs.So,powerful detection methods are vital and effective ways to prevent feed contamination.Traditional detection methods can no longer meet the needs of massive,real-time,simple,and fast mycotoxin monitoring.Rapid detection methods based on advanced material and sensor technology are the future trend.In this review,we highlight recent progress of mycotoxin rapid detection strategies in feedstuffs and foods,especially for simultaneous multiplex mycotoxin determination.Immunoassays,biosensors,and the prominent roles of nanomaterials are introduced.The principles of different types of recognition and signal transduction are explained,and the merits and pitfalls of these methods are compared.Furthermore,limitations and challenges of existing rapid sensing strategies and perspectives of future research are discussed.
文摘Capillary electrophoretic immunoassay with laser-induced fluorescence detection for recombinant human interferon-gamma (IFN-g) was established. The limits of detection for three forms of IFN-g are 6.9 ng/L, 5.7 ng/L and 5.0 ng/L, respectively.
文摘AIM: To evaluate cortisolemia by using conventional electrochemiluminescence immunoassay(ECLIA) method compared to liquid chromatography-tandem mass spectrometry(LC-MS/MS) method in active ulcerative colitis(UC) patients treated with oral prednisone(PD). METHODS: Twenty patients(12 males) with acute relapse of UC started oral PD at a dose of 40 mg once a day, tapered of 10 mg every 2 wk. When a stable 2-wk daily dose of 30 mg was reached, blood samples for cortisol levels' measurement were drawn in the morning in fasting conditions to determine circulating cortisol by LC-MS/MS and ECLIA assay. RESULTS: Median interquartile range cortisolemia with ECLIA and LC-MS/MS method was 54.1(185.8) nmol/L and 32.1(124.0) nmol/L, respectively(P < 0.001). The within-patient median differences between the two methods was 23.2(40.6) nmol/L, with higher cortisol levels for the ECLIA method. The estimated geomet-ric mean ratio between methods was 1.85(95%CI: 2.39-1.43) considering all data or 1.58(95%CI: 2.30-1.09) considering only data above the limit of quantification(n = 12). The 95%CIs of the geometric mean ratio between methods confirm a statistically significant difference.CONCLUSION: Blood cortisol levels detected with ECLIA method seems to be higher than the ones measured by LC-MS/MS, indicating a possible overestimation of them in patients treated with PD. Therefore, the cortisol suppression in patients under treatment with oral PD should not be measured using ECLIA method.
文摘Aldosterone quantification helps evaluate the rennin-angiotensin-aldosterone system. The new bead-based mul-tiplex platform has not been applied in aldosterone detection to achieve simultaneous measurements of multiple hormones. A new sensitive competitive bead immunoassay based on Luminex technology for detecting aldoster-one in small sample volumes was developed using two-antibody coupled beads and biotinylated aldosterone as tracer in combination with an extraction step. The assay was validated in human and mouse samples and exhibited a linear working range from 10 to 1,000 pg/mL. The assay was reproducible and precise with intra-assay coeffi-cient of variations (CVs) from 6.0% to 11.2%, inter-assay CVs from 8.0% to 13.0% and good recovery [(90-110)%] and linearity [(89-107)%]. Excellent correlation was found between this new assay and the reference method (r = 0.96, P 0.000,1). The successful establishment of this assay provides high possibility for carrying out bead-based multiplex assay measuring aldosterone and other parameters simultaneously in one 50 μL sample so that the efficiency can be improved and precious samples can be saved.
基金This project was supported by the National Natural Science Foundation of Chinathe Natural Science Foundation of Shandong Province and the State Key Laboratory of Electroanalytical Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Science.
文摘An electrochemical method for detection of cortisol based on capillary electrophoretic enzyme immunoassay has been developed. A limit of detection of 1.7?0-9 mol/L was obtained.
基金supported by the National Natural Science Foundation of Chinathe Natural Science Foundation of Shandong Provincethe Key State Laboratory of Electroanalytical Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences
文摘A Capillary electrophortic enzyme linked immunoassay with electrochemical detection (CE-EIA-ED) has been developed. The method can be used to determine thyroxine with a limit of 3.8×10-9 mol/L.
文摘BACKGROUND Current diagnosis of hepatitis C virus(HCV)infection requires two sequential steps:testing for anti-HCV followed by HCV RNA PCR to confirm viremia.We have developed a highly sensitive and specific HCV-antigens enzyme immunoassay(HCV-Ags EIA)for one-step diagnosis of viremic HCV infection.AIM To assess the clinical application of the HCV-Ags EIA in one-step diagnosis of viremic HCV infection in human immunodeficiency virus(HIV)-coinfected individuals.METHODS The study blindly tested HCV-Ags EIA for its performance in one-step diagnosing viremic HCV infection in 147 sera:10 without HCV or HIV infection;54 with viremic HCV monoinfection;38 with viremic HCV/HIV coinfection;and 45 with viremic HCV and non-viremic HIV coinfection.RESULTS Upon decoding,it was 100%accordance of HCV-Ags EIA to HCV infection status by HCV RNA PCR test.In five sera with HCV infection,HCV RNA was as low as 50-59 IU/mL,and four out of five tested positive for HCV-Ags EIA.Likewise,it was also 100%accordance of HCV-Ags EIA to HCV infection status by HCV RNA PCR in 83 sera with HCV and HIV coinfection,regardless if HIV infection was active or not.CONCLUSION The modified HCV-Ags EIA has a lower detection limit equivalent to serum HCV RNA levels of approximately 100 IU/mL.It is highly sensitive and specific in the setting of HIV coinfection,regardless of HIV infection status and CD4 count.These data support the clinical application of the HCV-Ags EIA in one-step diagnosis of HCV infection in HIV-infected individuals.
基金Supported by National Natural Science Foundation of China.
文摘We describe for the first time the synthesis and the optimal conditions for protein labeling with a new fluorescent probe,5-chlorosulfoyl-2-thenoyltrifluoroacetone(CTTA),whicb forms a highly fluorescent conplex with Eu^(3+) when conjugated to protein.The labeled proteins were characterized by absorbance and fluorescence measurements and the effect of labeling on the biological activity of sone proteins was also studied.It is shown that the new label is suitable for applications in time-resolved fluoroimmunoassay.