scholarly journals Development of a Competitive Lateral Flow Immunoassay for Progesterone in Dairy Cows’ Milk

2016 ◽  
Vol 72 (8) ◽  
pp. 494-497
Author(s):  
Chuang Xu ◽  
Wei Yang ◽  
Cheng Xia ◽  
Ling Wu ◽  
Hongyou Zhang
Keyword(s):  
Monoclonal Antibodies ◽  
Dairy Cows ◽  
Key Words ◽  
Test Line ◽  
Test Strip ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Pregnancy Diagnosis ◽  
Milk Samples ◽  
Routine Monitoring

The routine monitoring of progesterone, a hormone that plays important roles during pregnancy, has become increasingly important in dairy cows. In this study, 11α-OH-progesterone-hemisuccinate-BSA was used to immunize Balb/c mice for the preparation of mouse anti-progesterone monoclonal antibodies (mAbs). A competitive lateral flow immunoassay for progesterone was developed with the use of purified mAbs. Standard progesterone solutions or milk samples containing different concentrations of progesterone were added to the sample pad of the test strip. A bright or weak test line represented progesterone levels <3 ng> </tr> <tr> <td class="keywords">Key words: progesterone; lateral flow immunoassay; pregnancy diagnosis; dairy cows</td> </tr> </tbody>

scholarly journals Recombinase Polymerase Amplification (RPA) Combined with Lateral Flow Immunoassay for Rapid Detection of Salmonella in Food

Foods ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 27 ◽  
Author(s):  
Jiali Li ◽  
Biao Ma ◽  
Jiehong Fang ◽  
Antong Zhi ◽  
Erjing Chen ◽  
...  
Keyword(s):  
Test Line ◽  
Point Of Care ◽  
Limited Resource ◽  
Test Strip ◽  
Lateral Flow ◽  
Recombinase Polymerase Amplification ◽  
Lateral Flow Immunoassay ◽  
Quantitative Detection ◽  
Control Line ◽  
Test Strip Reader

Salmonella can cause serious foodborne diseases. We have developed a lateral flow immunoassay combined with recombinase polymerase amplification (LFD-RPA) for detection of Salmonella in food. The conserved fragment (fimY) was selected as the target gene. Under an optimal condition (37 °C, 10 min), the sensitivity was 12 colony-forming units (CFU)/mL in a pure culture. Testing with 16 non-Salmonella strains as controls revealed that LFD-RPA was specific to the fimY gene of Salmonella. The established assay could detect Salmonella at concentrations as low as 1.29 × 102 CFU/mL in artificially contaminated samples. This detection was at a slightly higher level than that for a pure bacterial culture. Combined with the test strip reader, the LFD-RPA is a feasible method for quantitative detection of Salmonella based on the test line intensity, which was the ratio for the test line and control line of the reflected light. The method could be a potential point-of-care test in limited resource areas and provides a new approach and technical support for the diagnosis of food safety.

An Aggregation-Induced Emission Material Labeling Antigen-Based Lateral Flow Immunoassay Strip for Rapid Detection of Escherichia coli O157:H7

2021 ◽  
pp. 247263032098193
Author(s):  
Cheng Liu ◽  
Shuiqin Fang ◽  
Yachen Tian ◽  
Youxue Wu ◽  
Meijiao Wu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rapid Detection ◽  
Foodborne Pathogen ◽  
Test Strip ◽  
Lateral Flow ◽  
Detection Sensitivity ◽  
Lateral Flow Immunoassay ◽  
Escherichia Coli O157 ◽  
Aggregation Induced Emission ◽  
E Coli

Escherichia coli O157:H7 ( E. coli O157:H7) is a dangerous foodborne pathogen, mainly found in beef, milk, fruits, and their products, causing harm to human health or even death. Therefore, the detection of E. coli O157:H7 in food is particularly important. In this paper, we report a lateral flow immunoassay strip (LFIS) based on aggregation-induced emission (AIE) material labeling antigen as a fluorescent probe for the rapid detection of E. coli O157:H7. The detection sensitivity of the strip is 105 CFU/mL, which is 10 times higher than that of the colloidal gold test strip. This method has good specificity and stability and can be used to detect about 250 CFU of E. coli O157:H7 successfully in 25 g or 25 mL of beef, jelly, and milk. AIE-LFIS might be valuable in monitoring food pathogens for rapid detection.

A rapid direct radioimmunoassay for the measurement of oestrone sulphate in the milk of dairy cows and its use in pregnancy diagnosis

1982 ◽  
Vol 95 (1) ◽  
pp. 7-12 ◽  
Author(s):  
R. J. Holdsworth ◽  
R. B. Heap ◽  
J. M. Booth ◽  
M. Hamon
Keyword(s):  
Dairy Cows ◽  
Dairy Herd ◽  
Pregnancy Diagnosis ◽  
Milk Samples ◽  
Oestrone Sulphate ◽  
Direct Assay ◽  
In Pregnancy

A radioimmunoassay for oestrone sulphate in unextracted samples of milk has been developed. The assay was validated by comparison with a method involving hydrolysis and extraction. The direct assay was used to measure oestrone sulphate in milk samples taken at weekly intervals throughout pregnancy in a commercial dairy herd. Concentrations of oestrone sulphate increased approximately 100 days after insemination and were maintained throughout the remainder of pregnancy in the range of 1·85–3·70 nmol/l.

scholarly journals Diagnostic accuracy of an app-guided, self-administered test for influenza among individuals presenting to general practice with influenza-like illness: study protocol

BMJ Open ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. e036298
Author(s):  
Victoria Lyon ◽  
Monica Zigman Suchsland ◽  
Monique Chilver ◽  
Nigel Stocks ◽  
Barry Lutz ◽  
...  
Keyword(s):  
Influenza A ◽  
Test Strip ◽  
Lateral Flow ◽  
Research Network ◽  
Lateral Flow Immunoassay ◽  
Rt Pcr ◽  
Test Procedures ◽  
Influenza Like Illness ◽  
Test Kit ◽  
Test Strip Reader

IntroductionDiagnostic tests for influenza in Australia are currently only authorised for use in clinical settings. At-home diagnostic testing for influenza could reduce the need for patient contact with healthcare services, which potentially could contribute to symptomatic improvement and reduced spread of influenza. We aim to determine the accuracy of an app-guided nasal self-swab combined with a lateral flow immunoassay for influenza conducted by individuals with influenza-like illness (ILI).Methods and analysisAdults (≥18 years) presenting with ILI will be recruited by general practitioners (GP) participating in Australian Sentinel Practices Research Network. Eligible participants will have a nasal swab obtained by their GP for verification of influenza A/B status using reverse transcription polymerase chain reaction (RT-PCR) test at an accredited laboratory. Participants will receive an influenza test kit and will download an app that collects self-reported symptoms and influenza risk factors, then instructs them in obtaining a low-nasal self-swab, running a QuickVue influenza A+B lateral flow immunoassay (Quidel Corporation) and interpreting the results. Participants will also interpret an enhanced image of the test strip in the app. The primary outcome will be the accuracy of participants’ test interpretation compared with the laboratory RT-PCR reference standard. Secondary analyses will include accuracy of the enhanced test strip image, accuracy of an automatic test strip reader algorithm and validation of prediction rules for influenza based on self-reported symptoms. A post-test survey will be used to obtain participant feedback on self-test procedures.Ethics and disseminationThe study was approved by the Human Research and Ethic Committee (HREC) at the University of Adelaide (H-2019-116). Protocol details and any amendments will be reported to https://www.tga.gov.au/. Results will be published in the peer-reviewed literature, and shared with stakeholders in the primary care and diagnostics communities.Trial registration numberAustralia New Zealand Clinical Trial Registry (U1111-1237-0688).

scholarly journals COVALENT CONJUGATION OF ANTIBODY AND GOLD NANOPARTICLE FOR DEVELOPMENT OF LATERAL FLOW IMMUNOASSAY TEST STRIP

2018 ◽  
Vol 54 (4A) ◽  
pp. 323
Author(s):  
Truong Quoc Phong
Keyword(s):  
Gold Nanoparticle ◽  
Room Temperature ◽  
Limit Of Detection ◽  
Coupling Reaction ◽  
Test Strip ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Research Fields ◽  
Antibody Conjugates ◽  
Antigen Antibody

Nanotechnology is one of the fastest growing technologies in this era. Gold nanoparticle (AuNP) based immunoassays have been performed on the basis of antigen-antibody interaction using AuNP antibody conjugates. Lateral flow immunoassays(LFA) which are also based on AuNP antibody conjugates are useful innovation in nanotechnology and widely applied in medicine and research fields. However, there are some limitations of the present LFA kits such as sensitivity and stability. In the study, we showed the result of covalent conjugation of anti-rotavirus antibody and AuNP for generating a lateral flow immunoassay strip to detect rotavirus in fecal samples. The suitable conditions for coating polyethylene glycol (PEG) on the surface of AuNP were 10.0 mM PEG for 3 hours at room temperature (25 oC). Optimized conditions for covalent conjugation of antibody and AuNP were pH 4.0, 0.1 mg antibody/conjugate, 0.01 mM reactant EDC/NHS [1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/(N-hydroxy sulfosuccinimide]. The coupling reaction was carried out at room temperature for 90 min. The conjugate pad, antibody immobilized nitrocellulose membrane strip were created with investigated conditions for generating an LFA test strip. The limit of detection of LFA test strip was determined by 1.6 × 105 virus particles/ml, three times lower than that of Rotaclone kit (UK). The generated strip could be used to detect rotavirus in fecal sample of patient. 

Multiplex lateral flow immunoassay for five antibiotics detection based on gold nanoparticle aggregations

RSC Advances ◽  
2016 ◽  
Vol 6 (10) ◽  
pp. 7798-7805 ◽  
Author(s):  
Juan Peng ◽  
Yongwei Wang ◽  
Liqiang Liu ◽  
Hua Kuang ◽  
Aike Li ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Gold Nanoparticle ◽  
Lateral Flow ◽  
Immunochromatographic Assay ◽  
Lateral Flow Immunoassay ◽  
Antibiotics Detection

A new immunochromatographic assay was developed for the simultaneous screening of five antibiotics that can coexist in milk, namely lincomycin, gentamicin, kanamycin, streptomycin, and neomycin, using five corresponding monoclonal antibodies.

scholarly journals An Attempt to Develop an Aptamer Lateral-Flow Assay (ALFA) for Easy, Rapid, and Sensitive Detection of Lethal Mushroom Toxin α-amanitin

2021 ◽  
Author(s):  
Qingchuan Chen ◽  
Chen Fan ◽  
Haozhe Huang ◽  
Binglin Xu ◽  
Yeqing Zong
Keyword(s):  
Test Line ◽  
Test Strip ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Detection Methods ◽  
Mushroom Poisoning ◽  
Control Line ◽  
Ph Tolerance ◽  
Higher Temperature ◽  
Target Binding

Amatoxins contribute to the majority of mushroom poisoning, most prominently, α-amanitin. Since mushroom is a common foodstuff worldwide, an easy, rapid, sensitive test for α-amanitin is needed. Several detection methods for α-amanitin have been developed, including HPLC, LC-MS, and ELISA, and LFIA. Aptamers have several advantages compared to antibodies: easy development via SELEX, longer shelf life, and higher temperature- and pH-tolerance. Aptamer Lateral Flow Assay (ALFA) is a similar technology compared to LFIA but incorporates aptamers as target-recognizing agents. This study attempted to develop an ALFA test strip for α-amanitin using a previously-developed aptamer, however failure of generating a colorimetric readout at the test line is persisted throughout all experiments, even though the concept is fully-proved and the control line functions normally. The failure is attributed to the small size of the molecule, leading to immobilization difficulties on the nitrocellulose membrane to form the test line, and the hindering of effective "surround" mechanism of aptamer-target binding (instead of "adhere", when the target molecule is large, e.g. a protein). It is concluded that ALFAs for small-molecules whose aptamer-target interaction has not yet been studied and modeled in detail remains a challenge, despite ALFAs' large potential.

Decreased fertility with increasing parity in lactating dairy cows

2008 ◽  
Vol 88 (3) ◽  
pp. 425-428 ◽  
Author(s):  
A. Balendran ◽  
M. Gordon ◽  
T. Pretheeban ◽  
R. Singh ◽  
R. Perera ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Treatment Group ◽  
Dairy Cows ◽  
Key Words ◽  
Pregnancy Rate ◽  
Research Centre ◽  
Key Words Pregnancy ◽  
Treatment Groups ◽  
Milk Samples ◽  
Lactating Dairy Cows

The relationships of parity and progesterone (P4) concentrations during the bred cycle with pregnancy rate (PR) were examined in this study. Breeding records of 163 Holstein heifers and cows (in 1st parity, 2nd parity, and 3rd or 4th parity) from the Uuniversity of British Columbia Dairy Education and Research Centre were used to compare PR among heifers, 1st, 2nd and 3rd/4th parity cows. Blood or milk samples collected from 10 animals of each treatment group were assayed to compare P4 concentrations among treatment groups. Statistical analysis showed that the heifers' first insemination PR (67.9%) was higher (P < 0.05) from 1st parity (42.9%), 2nd parity, (20.0%) and 3rd/4th parity cows (11.9%). P4 concentrations were not significantly different (P > 0.05). Key words: Pregnancy rate, progesterone, parity, cows, heifers

scholarly journals A two-colour multiplexed lateral flow immunoassay system to differentially detect human malaria species on a single test line

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Jinsu Kim ◽  
Xiangkun Elvis Cao ◽  
Julia L. Finkelstein ◽  
Washington B. Cárdenas ◽  
David Erickson ◽  
...  
Keyword(s):  
Test Line ◽  
Limit Of Detection ◽  
Simultaneous Detection ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Specific Marker ◽  
Single Test ◽  
Simple Method ◽  
Human Malaria ◽  
Malaria Species

Abstract Background Malaria continues to impose a tremendous burden in terms of global morbidity and mortality, yet even today, a large number of diagnoses are presumptive resulting in lack of or inappropriate treatment. Methods In this work, a two-colour lateral flow immunoassay (LFA) system was developed to identify infections by Plasmodium spp. and differentiate Plasmodium falciparum infection from the other three human malaria species (Plasmodium vivax, Plasmodium ovale, Plasmodium malariae). To achieve this goal, red and blue colours were encoded to two markers on a single test line of strips, for simultaneous detection of PfHRP2 (red), a marker specific for P. falciparum infection, and pLDH (blue), a pan-specific marker for infections by all species of Plasmodium. The assay performance was first optimized and evaluated with recombinant malarial proteins spiked in washing buffer at various concentrations from 0 to 1000 ng mL−1. The colour profiles developed on the single test line were discriminated and quantified: colour types corresponded to malaria protein species; colour intensities represented protein concentration levels. Results The limit of detection (the lowest concentrations of malaria antigens that can be distinguished from blank samples) and the limit of colour discrimination (the limit to differentiate pLDH from PfHRP2) were defined for the two-colour assay from the spiked buffer test, and the two limits were 31.2 ng mL−1 and 7.8 ng mL−1, respectively. To further validate the efficacy of the assay, 25 human whole blood frozen samples were tested and successfully validated against ELISA and microscopy results: 15 samples showed malaria negative; 5 samples showed P. falciparum positive; 5 samples showed P. falciparum negative, but contained other malaria species. Conclusions The assay provides a simple method to quickly identify and differentiate infection by different malarial parasites at the point-of-need and overcome the physical limitations of traditional LFAs, improving the multiplexing potential for simultaneous detection of various biomarkers.

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