Two rapid, sensitive and reliable immunoassay methods, namely competitive indirect enzyme-linked immunosorbent assay (CI-ELISA) and colloidal gold-based immunochromatographic assay (CGIA), were developed to detect ofl...Two rapid, sensitive and reliable immunoassay methods, namely competitive indirect enzyme-linked immunosorbent assay (CI-ELISA) and colloidal gold-based immunochromatographic assay (CGIA), were developed to detect ofloxacin (OFL). The linear range of the CI-ELISA was from 0.5 to 128 ng/mL with a limit of detection (LOD) of 0.35 ng/mL. Good recoveries were obtained in analyzing simulated swine urine samples. The CGIA could accurately estimate OFL at concentrations as low as 10 ng/mL in less than 10 min, and test results were read visually without any instrument.展开更多
Recently increasing concerns from the scientists and public have been paid for seawater pollution due to tetracycline(TC)overuse in maricultural area.However,there are few methods or instruments that can be used for s...Recently increasing concerns from the scientists and public have been paid for seawater pollution due to tetracycline(TC)overuse in maricultural area.However,there are few methods or instruments that can be used for specific and rapid detection of this antibiotic in seawater.In this study,the colloidal gold immunochromatographic assay(CG-ICA)was used to achieve this goal.A commercialized monoclonal antibody against TC(anti-TC mAb)was selected because of its higher sensitivity(half-maximal inhibitory concentration of 2.38μgL^(-1)).The prepared CG particles(average diameter of 20 nm)were used to label anti-TC mAb at pH 8.0.The conjugate pad was formed by spraying the CG-labeled anti-TC mAb on a glass fibre membrane followed by proper dryness.The test pad was made by immobilizing artificial antigen and anti-mouse mAb in the test line and the control line,respectively,in a nitrocellulose membrane.The test strip,assembled with sample pad,conjugate pad,test pad and absorbent pad,could be used to detect TC during seawater sample flowing through these components in turn.The results could be observed by the naked eye in 10min.The visible limit of detection(vLOD)was 20μgL^(-1) for TC in seawater.The CG-ICA test results were in good agreement with those of liquid chromatography-tandem mass spectrometry(LC-MS/MS).The assay also showed that,oxytetracycline(OTC)and chlortetracycline(CTC),as the structural analogues of TC,did not interfere with TC determination.Furthermore,the TC concentration given by test strip could not be affected by the fluctuation of temperature(10℃–30℃),pH(7–9)and salinity(0–40)of seawater.Therefore,CG-ICA is a suitable tool for rapid,on-site,and semi-quantitative detection of TC in seawater.展开更多
Colloidal gold immunochromatographic assay(CGIA)is commonly used for the on-site detection ofβ-agonists that are sometimes used illegally as feed additives in swine diets.However,few studies have evaluated the causes...Colloidal gold immunochromatographic assay(CGIA)is commonly used for the on-site detection ofβ-agonists that are sometimes used illegally as feed additives in swine diets.However,few studies have evaluated the causes of false-positive results that sometimes occur when applying CGIA in agricultural settings.In this study,we investigated if this false-positive phenomenon is related to the addition of certain traditional Chinese medicines(TCMs)to swine feed.We established and verified an extraction method for TCMs,and then applied CGIA to detectβ-agonists in the extracts of 105 TCMs and in the urine of swine dosed with TCMs,respectively.Liquid chromatography-tandem mass spectrometry was used to validate the results of the urine samples tested positive forβ-agonists using CGIA.The results were also verified using TCMs and colloidal gold test strips produced by different manufacturers.The extracts of Citri Reticulatae Pericarpium Viride,Citri Reticulatae Pericarpium,Magnoliae Officinalis Cortex,Chaenomelis Fructus,and Rhodiolae Crenulatae Radix Et Rhizoma were tested positive forβ-agonists.Meanwhile,the addition of Citri Reticulatae Pericarpium Viride and Citri Reticulatae Pericarpium to swine feed resulted in false-positive results forβ-agonists in swine urine.The results provide a new way to explain false-positive CGIA results and provide valuable information for livestock feeding programs.展开更多
Background:Colistin(polymyxin E)is a kind of peptide antibiotic which has been approved in animal production for the purposes of disease prevention,treatment,and growth promotion.However,the wide use of colistin in an...Background:Colistin(polymyxin E)is a kind of peptide antibiotic which has been approved in animal production for the purposes of disease prevention,treatment,and growth promotion.However,the wide use of colistin in animal feed may accelerate the spread of colistin-resistance gene MCR-1 from animal production to human beings,and its residue in animal-origin food may also pose serious health hazards to humans.Thus,it is necessary to develop corresponding analytical methods to monitor the addition of colistin in animal feed and the colistin residue in animal-origin food.Results:A one-step enzyme-linked immunosorbent assay(ELISA)and a lateral flow immunochromatographic assay(LFIA)for colistin were developed based on a newly developed monoclonal antibody.The ELISA showed a 50%inhibition value(IC50)of 9.7 ng/m L with assay time less than 60 min,while the LFIA had a strip reader-based detection limit of 0.87 ng/m L in phosphate buffer with assay time less than 15 min.For reducing the non-specific adsorption of colistin onto sample vial,the components of sample extraction solution were optimized and proved to greatly improve the assay accuracy.The spiked recovery experiment showed that the recoveries of colistin from feed,milk and meat samples were in the range of 77.83%to 113.38%with coefficient of variations less than 13%by ELISA analysis and less than 18%by LFIA analysis,respectively.Furthermore,actual sample analysis indicated that the two immunoassays can produce results consistent with instrumental analysis.Conclusions:The developed assays can be used for rapid qualitative or quantitative detection of colistin in animal feed and food.展开更多
A fluorescence immunochromatographic strip was developed in this study for natamycin detection in food. The results showed that the best amount of labeled antibody was 10 μg, for every 50 μl of fluorescent microsphe...A fluorescence immunochromatographic strip was developed in this study for natamycin detection in food. The results showed that the best amount of labeled antibody was 10 μg, for every 50 μl of fluorescent microspheres with a 2.5%(w/v) concentration. This labeled antibody was diluted for 10 times, and the diluted solution was dispensed into conjugate pad at the amount of 3 μl/cm. The concentrations of natamycin labeled BSA for test line and goat anti-mouse IgG for control line were 2.0 and 1 mg/ml, respectively, which performed best. With the best conditions, the limit of detection was 1 ng/ml, the linearity ranged from 2 to 100 ng/ml, the recovery was about 80% to 120%, and the CV was below 23%.展开更多
Among shrimp viral pathogens, white spot syndrome virus(WSSV) and yellow head virus(YHV) are the most lethal agents, causing serious problems for both the whiteleg shrimp, Penaeus(Litopenaeus) vannamei, and the black ...Among shrimp viral pathogens, white spot syndrome virus(WSSV) and yellow head virus(YHV) are the most lethal agents, causing serious problems for both the whiteleg shrimp, Penaeus(Litopenaeus) vannamei, and the black tiger shrimp, Penaeus(Penaeus) monodon. Another important virus that infects P. vannamei is infectious myonecrosis virus(IMNV), which induces the white discoloration of affected muscle. In the cases of taura syndrome virus and Penaeus stylirostris densovirus(Pst DNV; formerly known as infectious hypodermal and hematopoietic necrosis virus), their impacts were greatly diminished after the introduction of tolerant stocks of P. vannamei. Less important viruses are Penaeus monodon densovirus(Pm DNV; formerly called hepatopancreatic parvovirus), and Penaeus monodon nucleopolyhedrovirus(Pemo NPV; previously called monodon baculovirus). For freshwater prawn, Macrobrachium rosenbergii nodavirus and extra small virus are considered important viral pathogens. Monoclonal antibodies(MAbs) specific to the shrimp viruses described above have been generated and used as an alternative tool in various immunoassays such as enzyme-linked immunosorbent assay, dot blotting, Western blotting and immunohistochemistry. Some of these MAbs were further developed into immunochromatographic strip tests for the detection of WSSV, YHV, IMNV and Pemo NPV and into a dual strip test for the simultaneous detection of WSSV/YHV. The strip test has the advantages of speed, as the result can be obtained within 15 min, and simplicity, as laboratory equipment and specialized skills are not required. Therefore, strip tests can be used by shrimp farmers for the pond-side monitoring of viral infection.展开更多
A protein conjugate of streptomycin （streptomycin-bovine serum albumin （BSA） conjugate） was prepared and used as immunogen to produce monoclonal antibodies （MAb）. One hybridoma secreting anti-streptomycin MAb wa...A protein conjugate of streptomycin （streptomycin-bovine serum albumin （BSA） conjugate） was prepared and used as immunogen to produce monoclonal antibodies （MAb）. One hybridoma secreting anti-streptomycin MAb was obtained and then used to produce MAb. The MAb named 13H5 showed the 50% maximal inhibitory concentra- tion （IC50） value of 4.65 ng/ml and the IC20value of 0.21 ng/ml in phosphate buffered saline （PBS）. At optimum con- ditions, an indirect competitive enzyme-linked immunosorbent assay （ELISA） and a colloidal gold-based immuno- chromatographic assay （CGIA） were developed and applied to detect streptomycin residues in milk and swine urine samples. The developed ELISA showed that the minimum detection limit was 2.0 and 1.9 ng/ml for milk and swine urine samples, respectively, without obvious cross-reactivity to other tested antibiotics except dihydrostreptomycin which gave a 118.32% cross reaction value. Milk and swine urine samples spiked with streptomycin at 10, 50, 100 and 200 ng/rnl were analyzed by the established ELISA. The mean recovery of streptomycin was from 81.9% to 105.5% and from 84.3% to 92.2% for milk and swine urine, respectively. The optimized CGIA showed that the minimum de- tection limit was 20.0 ng/ml for milk and swine urine samples. The results of spiked analysis and specific analysis demonstrate that the CGIA could be applicable for screening milk and swine urine samples for the presence of streptomycin residues on-site. The established ELISA and CGIA allow the rapid, low-cost, and sensitive determination of streptomycin residues in food samples.展开更多
A one-step dual flow immunochromatographic assay （DICGA）, based on a competitive format, was de- veloped for simultaneous quantification of ochratoxin A （OTA） and zearalenone （ZEN） in corn, wheat, and feed sam- ...A one-step dual flow immunochromatographic assay （DICGA）, based on a competitive format, was de- veloped for simultaneous quantification of ochratoxin A （OTA） and zearalenone （ZEN） in corn, wheat, and feed sam- ples. The limit of detection for OTA was 0.32 ng/ml with a detection range of 0.53-12.16 ng/ml, while for ZEN it was 0.58 ng/ml with a detection range of 1.06-39.72 ng/ml. The recovery rates in corn, wheat, and feed samples ranged from 77.3% to 106.3% with the coefficient of variation lower than 15%. Naturally contaminated corn, wheat, and feed samples were analyzed using both DICGA and liquid chromatography-tandem mass spectrometry （LC-MS/MS） and the correlation between the two methods was evaluated using a regression analysis. The DICGA method shows great potential for simple, rapid, sensitive, and cost-effective quantitative detection of OTA and ZEN in food safety control.展开更多
Paclitaxel(PTX),methotrexate(MTX),and 5-fluorouracil(5-FU)are commonly-used small molecule anti-tumor drugs for breast cancer.Unfortunately,drug resistance occurs with long-term treatment or excessive use,and the high...Paclitaxel(PTX),methotrexate(MTX),and 5-fluorouracil(5-FU)are commonly-used small molecule anti-tumor drugs for breast cancer.Unfortunately,drug resistance occurs with long-term treatment or excessive use,and the high concentrations of PTX,MTX,and 5-FU in patients may lead to side effects with dose-limiting toxicities,such as myelosuppression,hepatotoxicity,and peripheral neuropathy.Therefore,concentration monitoring of PTX,MTX,and 5-FU in clinical treatment is very important.We prepared highly sensitive and specific monoclonal antibodies using several haptens,and established a multiple paper-based sensor utilizing optical signals of gold nanoparticles,which simultaneously detected PTX,MTX,and 5-FU in human plasma or urine with 10 min.A portable scanner for quantitative detection in plasma and urine samples was used,and the calculated limit of detection(cLOD)values were 0.002 and 0.142μg/mL for PTX,0.187 and 0.976 ng/mL for MTX,and 0.057 and 0.128μg/mL for 5-FU,respectively.In the recovery test,the recovery rates and the coefficient of variation were 85.84%–108.81%and 1.23%–8.80%,respectively,indicating the reliability and accuracy of the multiple gold immunochromatographic strip(GIS).In addition,for the determination of collected clinical plasma samples,the correlation between the test data of the multiple GIS and liquid chromatography–tandem mass spectrometry(LC–MS/MS)was good.Therefore,the developed multiple GIS could be applied to the rapid detection of PTX,MTX,and 5-FU in different clinical samples.展开更多
Herbicide residues in agricultural products can have adverse effects on the environment and human health,therefore,there is an urgent need to establish a sensitive,rapid,and wide-ranging detection method.In this study...Herbicide residues in agricultural products can have adverse effects on the environment and human health,therefore,there is an urgent need to establish a sensitive,rapid,and wide-ranging detection method.In this study,haptens of phenylurea herbicides(PUs)and sulfonylurea herbicides(SUs)were analyzed and designed based on computational simulation techniques,and two high-performance broad-spectrum monoclonal antibodies against PUs and SUs were prepared.On this basis,a multi-colloidal gold immunochromatography assay(multi-CGIA)was developed to simultaneously detect 13 herbicides in wheat.The visual limit of detection(vLOD)for PUs including diuron,chlortoluron,neburon,chlorbromuron,and linuron was 1-2μg/kg.The vLOD for SUs including metsulfuron methyl,ethametsulfuron-methyl,sulfometuron-methyl,tribenuron methyl,cinosulfuron,triasulfuron,chlorimuron-ethyl,and chlorsulfuron was 2-10μg/kg.The results of real sample determination indicated that the multi-CGIA is accurate,stable,and reliable,and adaptable to on-site preliminary screening of actual samples.展开更多
Difenoconazole is triazole fungicide,widely used to prevent the growth and reproduction of fungi and to control fungal diseases in fruits and vegetables.In this work,we prepared a hapten of difenoconazole and produced...Difenoconazole is triazole fungicide,widely used to prevent the growth and reproduction of fungi and to control fungal diseases in fruits and vegetables.In this work,we prepared a hapten of difenoconazole and produced a highly-sensitive anti difenoconazole-monoclonal antibody(mAb)with an IC50 of 0.64 ng/mL.Using the mAb,an immunochromatographic assay(ICA)was developed to analyze difenoconazole residues in pear and cucumber samples.The ICA exhibited LOD values of 2.60 and 2.30 ng/g for difenoconazole in pear and cucumber samples,respectively.The ICA showed average recoveries of difenoconazole ranging from 94.3%±3.6%–105.4%±1.6%,and CVs of 1.5–4.2%in cucumber and pear samples.When used to measure difenoconazole in samples,the ICA results were compatible with those detected by LC/MSMS.The results of this study support the idea that an ICA is a practical and effective tool for high-throughput and rapid analysis of difenoconazole residues in vegetables and fruits.展开更多
Objectives:Based on the information from the random inspection of foods by the China Food and Drug Administration in 2022,the contamin-ation levels of lead ions are high in many edible products.Traditional methods of ...Objectives:Based on the information from the random inspection of foods by the China Food and Drug Administration in 2022,the contamin-ation levels of lead ions are high in many edible products.Traditional methods of detecting lead ions cannot meet the requirements of on-site analysis of food due to the need for large equipment.The immunochromatographic assay(iCA)is an effective,rapid,on-site analytical technique for determining lead ions in foods.However,the performance of ICA based on the traditional probe(AuNP-mAb)is limited by ignoring the influ-ence of theantibody orientation.Materials and Methods:In this study,we developed an efficient technology for constructing a universal probe(AuNP-PrA-mAb)based on the oriented immobilization of antibody.The performance of ICA was largely improved due to specific binding of the Fc region of the antibody with recombinant protein A(PrA)on the surface of a gold nanoparticle(AuNP).The ICA based on a universal probe was applied for the qualitative and quantitative detection of lead ions in Procambarus clarki within 30 min.Meanwhile,a simple and fast pretreatment method based on dilute acid extraction was developed forpretreating thePclarkii containing leadions.Results:The visual limit of detection and the scanning limit of quantization of the developed iCA strip for lead ions were O.5 ng/mL and 0.28 ng/mL,respectively.The sensitivity of ICA based on universal probe was 10-fold higher than that of the ICA using traditional probe.Furthermore,the detection results had no obvious difference between the ICA and ICP-MS with t-test statistical method.Conclusions:The developed ICA based on a universal probe presented broad application prospects in detecting contaminants in foods.展开更多
Synthetic contraceptive levonorgestrel （LNG） and glucocorticoid methylprednisolone （MP） residues are eventually discarded to environmental water system and function as environmental hormones, displaying potential ...Synthetic contraceptive levonorgestrel （LNG） and glucocorticoid methylprednisolone （MP） residues are eventually discarded to environmental water system and function as environmental hormones, displaying potential risk to humans and ecosystems, thus there is an urgent need for fast, sensitive and simultaneous detection of these compounds in water samples. In this study, a competitive immunochromatographic assay （ICA） using colloidal gold-labeled polyclonal antibodies as probes for rapid and simultaneous detection of LNG and MP in water samples was developed. The visual detection limits of LNG and MP in water samples were 10 ng/mL. The detection process could be completed within 10 min. There was no cross-reactivity of the ICA with other seven compounds. The strips could be stored at 4 ℃ for 10 weeks without significant loss of activity. The assay is a suitable tool for rapid and semi- quantitative detection of LNG and MP in water samples on site.展开更多
Procalcitonin （PCT） is a sensitive and specific biomarker for sepsis diagnosis and widely used as a biomarker to improve the diagnosis of bacterial infections and to guide the antibiotic therapy. In our work, an imp...Procalcitonin （PCT） is a sensitive and specific biomarker for sepsis diagnosis and widely used as a biomarker to improve the diagnosis of bacterial infections and to guide the antibiotic therapy. In our work, an improved up-converting nanoparticle （UCP） technology based on the immunochromatographic assay （UPT-ICA） was developed for rapid and quantitative detection of PCT. In order to further improve the accuracy, sensitivity and stability of the assay on the basis of our previous study, the UCP coupling with rnonoclonal antibody of PCT （UCP-Abl） was freeze-dried under certain conditions. And the detections of PCT levels with UCP-Abl conjugates before and after freeze-drying were evaluated. The results show that, compared to the UCP-Abl conjugates without freeze-drying, the detection sensitivity of freeze-dried UCP-Abl is slightly improved, having a lower immunochromatogragh background and better stability. This improved method can provide a rapid, accurate, and relatively easy way for the clinical detection of PCT.展开更多
文摘Two rapid, sensitive and reliable immunoassay methods, namely competitive indirect enzyme-linked immunosorbent assay (CI-ELISA) and colloidal gold-based immunochromatographic assay (CGIA), were developed to detect ofloxacin (OFL). The linear range of the CI-ELISA was from 0.5 to 128 ng/mL with a limit of detection (LOD) of 0.35 ng/mL. Good recoveries were obtained in analyzing simulated swine urine samples. The CGIA could accurately estimate OFL at concentrations as low as 10 ng/mL in less than 10 min, and test results were read visually without any instrument.
基金The authors acknowledge the financial support from the National Natural Science Foundation of China(No.42077335).
文摘Recently increasing concerns from the scientists and public have been paid for seawater pollution due to tetracycline(TC)overuse in maricultural area.However,there are few methods or instruments that can be used for specific and rapid detection of this antibiotic in seawater.In this study,the colloidal gold immunochromatographic assay(CG-ICA)was used to achieve this goal.A commercialized monoclonal antibody against TC(anti-TC mAb)was selected because of its higher sensitivity(half-maximal inhibitory concentration of 2.38μgL^(-1)).The prepared CG particles(average diameter of 20 nm)were used to label anti-TC mAb at pH 8.0.The conjugate pad was formed by spraying the CG-labeled anti-TC mAb on a glass fibre membrane followed by proper dryness.The test pad was made by immobilizing artificial antigen and anti-mouse mAb in the test line and the control line,respectively,in a nitrocellulose membrane.The test strip,assembled with sample pad,conjugate pad,test pad and absorbent pad,could be used to detect TC during seawater sample flowing through these components in turn.The results could be observed by the naked eye in 10min.The visible limit of detection(vLOD)was 20μgL^(-1) for TC in seawater.The CG-ICA test results were in good agreement with those of liquid chromatography-tandem mass spectrometry(LC-MS/MS).The assay also showed that,oxytetracycline(OTC)and chlortetracycline(CTC),as the structural analogues of TC,did not interfere with TC determination.Furthermore,the TC concentration given by test strip could not be affected by the fluctuation of temperature(10℃–30℃),pH(7–9)and salinity(0–40)of seawater.Therefore,CG-ICA is a suitable tool for rapid,on-site,and semi-quantitative detection of TC in seawater.
基金the Guangdong Public Welfare Research and Capacity Building Project,China(2015A020209130)。
文摘Colloidal gold immunochromatographic assay(CGIA)is commonly used for the on-site detection ofβ-agonists that are sometimes used illegally as feed additives in swine diets.However,few studies have evaluated the causes of false-positive results that sometimes occur when applying CGIA in agricultural settings.In this study,we investigated if this false-positive phenomenon is related to the addition of certain traditional Chinese medicines(TCMs)to swine feed.We established and verified an extraction method for TCMs,and then applied CGIA to detectβ-agonists in the extracts of 105 TCMs and in the urine of swine dosed with TCMs,respectively.Liquid chromatography-tandem mass spectrometry was used to validate the results of the urine samples tested positive forβ-agonists using CGIA.The results were also verified using TCMs and colloidal gold test strips produced by different manufacturers.The extracts of Citri Reticulatae Pericarpium Viride,Citri Reticulatae Pericarpium,Magnoliae Officinalis Cortex,Chaenomelis Fructus,and Rhodiolae Crenulatae Radix Et Rhizoma were tested positive forβ-agonists.Meanwhile,the addition of Citri Reticulatae Pericarpium Viride and Citri Reticulatae Pericarpium to swine feed resulted in false-positive results forβ-agonists in swine urine.The results provide a new way to explain false-positive CGIA results and provide valuable information for livestock feeding programs.
基金financially supported by Beijing Advanced Innovation Center for Food Nutrition and Human HealthBasic Research Program of Science and Technology(2014FY111000).
文摘Background:Colistin(polymyxin E)is a kind of peptide antibiotic which has been approved in animal production for the purposes of disease prevention,treatment,and growth promotion.However,the wide use of colistin in animal feed may accelerate the spread of colistin-resistance gene MCR-1 from animal production to human beings,and its residue in animal-origin food may also pose serious health hazards to humans.Thus,it is necessary to develop corresponding analytical methods to monitor the addition of colistin in animal feed and the colistin residue in animal-origin food.Results:A one-step enzyme-linked immunosorbent assay(ELISA)and a lateral flow immunochromatographic assay(LFIA)for colistin were developed based on a newly developed monoclonal antibody.The ELISA showed a 50%inhibition value(IC50)of 9.7 ng/m L with assay time less than 60 min,while the LFIA had a strip reader-based detection limit of 0.87 ng/m L in phosphate buffer with assay time less than 15 min.For reducing the non-specific adsorption of colistin onto sample vial,the components of sample extraction solution were optimized and proved to greatly improve the assay accuracy.The spiked recovery experiment showed that the recoveries of colistin from feed,milk and meat samples were in the range of 77.83%to 113.38%with coefficient of variations less than 13%by ELISA analysis and less than 18%by LFIA analysis,respectively.Furthermore,actual sample analysis indicated that the two immunoassays can produce results consistent with instrumental analysis.Conclusions:The developed assays can be used for rapid qualitative or quantitative detection of colistin in animal feed and food.
基金Supported by Ningbo Entry-Exit Inspection and Quarantine Bureau(Ningbo Customs)Science and Technology Project(YK07-2017)
文摘A fluorescence immunochromatographic strip was developed in this study for natamycin detection in food. The results showed that the best amount of labeled antibody was 10 μg, for every 50 μl of fluorescent microspheres with a 2.5%(w/v) concentration. This labeled antibody was diluted for 10 times, and the diluted solution was dispensed into conjugate pad at the amount of 3 μl/cm. The concentrations of natamycin labeled BSA for test line and goat anti-mouse IgG for control line were 2.0 and 1 mg/ml, respectively, which performed best. With the best conditions, the limit of detection was 1 ng/ml, the linearity ranged from 2 to 100 ng/ml, the recovery was about 80% to 120%, and the CV was below 23%.
基金Srinakharinwirot University, the Thai National Center for Genetic Engineering and Biotechnology, the Thailand Research Fund, Office of Higher Education Commission, Ministry of Education, Thailand for their funding supports to our research works
文摘Among shrimp viral pathogens, white spot syndrome virus(WSSV) and yellow head virus(YHV) are the most lethal agents, causing serious problems for both the whiteleg shrimp, Penaeus(Litopenaeus) vannamei, and the black tiger shrimp, Penaeus(Penaeus) monodon. Another important virus that infects P. vannamei is infectious myonecrosis virus(IMNV), which induces the white discoloration of affected muscle. In the cases of taura syndrome virus and Penaeus stylirostris densovirus(Pst DNV; formerly known as infectious hypodermal and hematopoietic necrosis virus), their impacts were greatly diminished after the introduction of tolerant stocks of P. vannamei. Less important viruses are Penaeus monodon densovirus(Pm DNV; formerly called hepatopancreatic parvovirus), and Penaeus monodon nucleopolyhedrovirus(Pemo NPV; previously called monodon baculovirus). For freshwater prawn, Macrobrachium rosenbergii nodavirus and extra small virus are considered important viral pathogens. Monoclonal antibodies(MAbs) specific to the shrimp viruses described above have been generated and used as an alternative tool in various immunoassays such as enzyme-linked immunosorbent assay, dot blotting, Western blotting and immunohistochemistry. Some of these MAbs were further developed into immunochromatographic strip tests for the detection of WSSV, YHV, IMNV and Pemo NPV and into a dual strip test for the simultaneous detection of WSSV/YHV. The strip test has the advantages of speed, as the result can be obtained within 15 min, and simplicity, as laboratory equipment and specialized skills are not required. Therefore, strip tests can be used by shrimp farmers for the pond-side monitoring of viral infection.
基金Project (No.2007C22047) supported by the Program of Science and Technology of Zhejiang Province,China
文摘A protein conjugate of streptomycin （streptomycin-bovine serum albumin （BSA） conjugate） was prepared and used as immunogen to produce monoclonal antibodies （MAb）. One hybridoma secreting anti-streptomycin MAb was obtained and then used to produce MAb. The MAb named 13H5 showed the 50% maximal inhibitory concentra- tion （IC50） value of 4.65 ng/ml and the IC20value of 0.21 ng/ml in phosphate buffered saline （PBS）. At optimum con- ditions, an indirect competitive enzyme-linked immunosorbent assay （ELISA） and a colloidal gold-based immuno- chromatographic assay （CGIA） were developed and applied to detect streptomycin residues in milk and swine urine samples. The developed ELISA showed that the minimum detection limit was 2.0 and 1.9 ng/ml for milk and swine urine samples, respectively, without obvious cross-reactivity to other tested antibiotics except dihydrostreptomycin which gave a 118.32% cross reaction value. Milk and swine urine samples spiked with streptomycin at 10, 50, 100 and 200 ng/rnl were analyzed by the established ELISA. The mean recovery of streptomycin was from 81.9% to 105.5% and from 84.3% to 92.2% for milk and swine urine, respectively. The optimized CGIA showed that the minimum de- tection limit was 20.0 ng/ml for milk and swine urine samples. The results of spiked analysis and specific analysis demonstrate that the CGIA could be applicable for screening milk and swine urine samples for the presence of streptomycin residues on-site. The established ELISA and CGIA allow the rapid, low-cost, and sensitive determination of streptomycin residues in food samples.
基金Project supported by the Natural Science Foundation of Zhejiang Province(No.LQ17C170002)the Talent-Start Project of Zhejiang A&F University(No.2016FR025)+1 种基金the Key Research and Development Project Funds of Zhejiang Provincial Science and Technology Department(No.2018C02041)and the National High-Tech R&D Program(863)of China(No.2012AA101602)
文摘A one-step dual flow immunochromatographic assay （DICGA）, based on a competitive format, was de- veloped for simultaneous quantification of ochratoxin A （OTA） and zearalenone （ZEN） in corn, wheat, and feed sam- ples. The limit of detection for OTA was 0.32 ng/ml with a detection range of 0.53-12.16 ng/ml, while for ZEN it was 0.58 ng/ml with a detection range of 1.06-39.72 ng/ml. The recovery rates in corn, wheat, and feed samples ranged from 77.3% to 106.3% with the coefficient of variation lower than 15%. Naturally contaminated corn, wheat, and feed samples were analyzed using both DICGA and liquid chromatography-tandem mass spectrometry （LC-MS/MS） and the correlation between the two methods was evaluated using a regression analysis. The DICGA method shows great potential for simple, rapid, sensitive, and cost-effective quantitative detection of OTA and ZEN in food safety control.
基金financially supported by the National Natural Science Foundation of China(Nos.22236002 and 21925402)this work is also financially supported by National Key R&D Program(No.2021YFA1200300).
文摘Paclitaxel(PTX),methotrexate(MTX),and 5-fluorouracil(5-FU)are commonly-used small molecule anti-tumor drugs for breast cancer.Unfortunately,drug resistance occurs with long-term treatment or excessive use,and the high concentrations of PTX,MTX,and 5-FU in patients may lead to side effects with dose-limiting toxicities,such as myelosuppression,hepatotoxicity,and peripheral neuropathy.Therefore,concentration monitoring of PTX,MTX,and 5-FU in clinical treatment is very important.We prepared highly sensitive and specific monoclonal antibodies using several haptens,and established a multiple paper-based sensor utilizing optical signals of gold nanoparticles,which simultaneously detected PTX,MTX,and 5-FU in human plasma or urine with 10 min.A portable scanner for quantitative detection in plasma and urine samples was used,and the calculated limit of detection(cLOD)values were 0.002 and 0.142μg/mL for PTX,0.187 and 0.976 ng/mL for MTX,and 0.057 and 0.128μg/mL for 5-FU,respectively.In the recovery test,the recovery rates and the coefficient of variation were 85.84%–108.81%and 1.23%–8.80%,respectively,indicating the reliability and accuracy of the multiple gold immunochromatographic strip(GIS).In addition,for the determination of collected clinical plasma samples,the correlation between the test data of the multiple GIS and liquid chromatography–tandem mass spectrometry(LC–MS/MS)was good.Therefore,the developed multiple GIS could be applied to the rapid detection of PTX,MTX,and 5-FU in different clinical samples.
基金supported by the National Natural Science Foundation of China(Nos.22306074 and 222360020)the National Key Research and Development Program of China(Nos.2023YFF1105003 and 2022YFA1207300)the grants from Jiangsu province(Nos.CX(22)1013,BK20212014,and M20221006).
文摘Herbicide residues in agricultural products can have adverse effects on the environment and human health,therefore,there is an urgent need to establish a sensitive,rapid,and wide-ranging detection method.In this study,haptens of phenylurea herbicides(PUs)and sulfonylurea herbicides(SUs)were analyzed and designed based on computational simulation techniques,and two high-performance broad-spectrum monoclonal antibodies against PUs and SUs were prepared.On this basis,a multi-colloidal gold immunochromatography assay(multi-CGIA)was developed to simultaneously detect 13 herbicides in wheat.The visual limit of detection(vLOD)for PUs including diuron,chlortoluron,neburon,chlorbromuron,and linuron was 1-2μg/kg.The vLOD for SUs including metsulfuron methyl,ethametsulfuron-methyl,sulfometuron-methyl,tribenuron methyl,cinosulfuron,triasulfuron,chlorimuron-ethyl,and chlorsulfuron was 2-10μg/kg.The results of real sample determination indicated that the multi-CGIA is accurate,stable,and reliable,and adaptable to on-site preliminary screening of actual samples.
基金supported by the National Key Research and Development Program of China(2019YFC1604503).
文摘Difenoconazole is triazole fungicide,widely used to prevent the growth and reproduction of fungi and to control fungal diseases in fruits and vegetables.In this work,we prepared a hapten of difenoconazole and produced a highly-sensitive anti difenoconazole-monoclonal antibody(mAb)with an IC50 of 0.64 ng/mL.Using the mAb,an immunochromatographic assay(ICA)was developed to analyze difenoconazole residues in pear and cucumber samples.The ICA exhibited LOD values of 2.60 and 2.30 ng/g for difenoconazole in pear and cucumber samples,respectively.The ICA showed average recoveries of difenoconazole ranging from 94.3%±3.6%–105.4%±1.6%,and CVs of 1.5–4.2%in cucumber and pear samples.When used to measure difenoconazole in samples,the ICA results were compatible with those detected by LC/MSMS.The results of this study support the idea that an ICA is a practical and effective tool for high-throughput and rapid analysis of difenoconazole residues in vegetables and fruits.
基金supported by the National Natural Science Foundation of China(No.32102072).
文摘Objectives:Based on the information from the random inspection of foods by the China Food and Drug Administration in 2022,the contamin-ation levels of lead ions are high in many edible products.Traditional methods of detecting lead ions cannot meet the requirements of on-site analysis of food due to the need for large equipment.The immunochromatographic assay(iCA)is an effective,rapid,on-site analytical technique for determining lead ions in foods.However,the performance of ICA based on the traditional probe(AuNP-mAb)is limited by ignoring the influ-ence of theantibody orientation.Materials and Methods:In this study,we developed an efficient technology for constructing a universal probe(AuNP-PrA-mAb)based on the oriented immobilization of antibody.The performance of ICA was largely improved due to specific binding of the Fc region of the antibody with recombinant protein A(PrA)on the surface of a gold nanoparticle(AuNP).The ICA based on a universal probe was applied for the qualitative and quantitative detection of lead ions in Procambarus clarki within 30 min.Meanwhile,a simple and fast pretreatment method based on dilute acid extraction was developed forpretreating thePclarkii containing leadions.Results:The visual limit of detection and the scanning limit of quantization of the developed iCA strip for lead ions were O.5 ng/mL and 0.28 ng/mL,respectively.The sensitivity of ICA based on universal probe was 10-fold higher than that of the ICA using traditional probe.Furthermore,the detection results had no obvious difference between the ICA and ICP-MS with t-test statistical method.Conclusions:The developed ICA based on a universal probe presented broad application prospects in detecting contaminants in foods.
基金fnancial support from the National Natural Science Foundation of China(No.21175097)
文摘Synthetic contraceptive levonorgestrel （LNG） and glucocorticoid methylprednisolone （MP） residues are eventually discarded to environmental water system and function as environmental hormones, displaying potential risk to humans and ecosystems, thus there is an urgent need for fast, sensitive and simultaneous detection of these compounds in water samples. In this study, a competitive immunochromatographic assay （ICA） using colloidal gold-labeled polyclonal antibodies as probes for rapid and simultaneous detection of LNG and MP in water samples was developed. The visual detection limits of LNG and MP in water samples were 10 ng/mL. The detection process could be completed within 10 min. There was no cross-reactivity of the ICA with other seven compounds. The strips could be stored at 4 ℃ for 10 weeks without significant loss of activity. The assay is a suitable tool for rapid and semi- quantitative detection of LNG and MP in water samples on site.
基金Supporting information for this article is available on the WWW under http：//dx.doi.org/10.1002/cjoc.201700354.Acknowledgement This work was supported by the NSFC （National Natural Science Foundation of China） （No. 21176124）. Affinity-purified monoclonal antibody of PCT, PCT antigen and affinity-purified antibody from goat anti mouse IgG were all obtained from Nanjing Norman Biological Technology Co., Ltd.
文摘Procalcitonin （PCT） is a sensitive and specific biomarker for sepsis diagnosis and widely used as a biomarker to improve the diagnosis of bacterial infections and to guide the antibiotic therapy. In our work, an improved up-converting nanoparticle （UCP） technology based on the immunochromatographic assay （UPT-ICA） was developed for rapid and quantitative detection of PCT. In order to further improve the accuracy, sensitivity and stability of the assay on the basis of our previous study, the UCP coupling with rnonoclonal antibody of PCT （UCP-Abl） was freeze-dried under certain conditions. And the detections of PCT levels with UCP-Abl conjugates before and after freeze-drying were evaluated. The results show that, compared to the UCP-Abl conjugates without freeze-drying, the detection sensitivity of freeze-dried UCP-Abl is slightly improved, having a lower immunochromatogragh background and better stability. This improved method can provide a rapid, accurate, and relatively easy way for the clinical detection of PCT.
