Multiple Labeling of Antibodies with Dye/DNA Conjugate for Sensitivity Improvement in Fluorescence Immunoassay

2007 ◽  
Vol 18 (5) ◽  
pp. 1668-1672 ◽  
Author(s):  
Qin Zhang ◽  
Liang-Hong Guo
Keyword(s):  
Fluorescence Immunoassay ◽  
Sensitivity Improvement

scholarly journals Ball-lens assisted sensitivity improvement of fluorescence immunoassay in microchannels

RSC Advances ◽  
2021 ◽  
Vol 11 (44) ◽  
pp. 27541-27546
Author(s):  
Qingquan Zhang ◽  
Jiajia Li ◽  
Yuting Su ◽  
Xiaoyan Pan ◽  
Hongwei Gai
Keyword(s):  
Fluorescence Immunoassay ◽  
Improvement Method ◽  
Sensitivity Improvement

A contactless and ball-lens assisted sensitivity improvement method was present for the fluorescence or luminescence immunoassay in microchannel.

Immunofluorescence Assay Using Monoclonal and Polyclonal Antibodies for Detection of Staphylococcal Enterotoxins A in Milk

2019 ◽  
Vol 13 (1) ◽  
pp. 137-145 ◽  
Author(s):  
Tzonka Godjevargova ◽  
Zlatina Becheva ◽  
Yavor Ivanov ◽  
Andrey Tchorbanov
Keyword(s):  
Monoclonal Antibody ◽  
Magnetic Nanoparticles ◽  
Polyclonal Antibody ◽  
Polyclonal Antibodies ◽  
Food Poisoning ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin A ◽  
Fluorescence Immunoassay ◽  
Magnetic Separator ◽  
Milk Samples

Objectives: Staphylococcus aureus is a Gram-positive microorganism. S. aureus can grow in various foods and cause food poisoning by secreting enterotoxins. The most common enterotoxins involved in food poisoning are staphylococcal enterotoxin A and staphylococcal enterotoxin B, but Staphylococcal Enterotoxin A (SEA) is predominant. The main types of food contaminated with SEs are meat and meat products, poultry and eggs, milk and dairy products. The aim of this study was to develop a rapid and sensitive fluorescence immunoassay for detection of staphylococcal enterotoxin A in milk. Methods: Monoclonal and polyclonal antibodies for SEA were produced and characterized. Competitive fluorescence immunoassay based on Magnetic Nanoparticles (MNPs) was performed and optimized. MNPs were used as a solid carrier of the antibodies. The first step of the assay was immunoreaction between the immobilized antibody onto MNPs and SEA in milk sample. Then the fluorescein-SEA conjugate was added to the sample. Thus, competitive immunoreaction between MNP-mAb/MNP-pAb with SEA and SEA-FITC was performed. These immuno-complexes were separated by a magnetic separator and the obtained supernatants were analyzed. The fluorescent signal from the excess of conjugated SEA was proportional to the SEA contained in the milk. The assay duration was only 30 min. Results: The fluorescence immunoassays performed with polyclonal antibody had linear ranges from 5 pg/mL to 100 ng/mL SEA in a buffer, and from 50 pg/mL to 50 ng/mL SEA in spiked milk samples. While the same assays performed with monoclonal antibody had linear ranges from 1 pg/mL to 20 ng/mL SEA in buffer, and from 10 pg/mL to 10 ng/mL SEA in spiked milk samples. The detection limits of the developed immunoassays performed in milk were: 48 pg/mL with polyclonal antibody and 9 pg/mL with monoclonal antibody. Conclusion: A rapid and sensitive fluorescence immunoassay based on magnetic nanoparticles with a polyclonal and monoclonal antibody for determination of staphylococcal enterotoxin A in milk was developed.

scholarly journals Development of a multicolor upconversion fluorescence immunoassay for the simultaneous detection of thiamethoxam and dextran by magnetic separation

RSC Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 517-524
Author(s):  
Chuanyong Li ◽  
Wanlin Sun ◽  
Lianrun Huang ◽  
Nana Sun ◽  
Xiude Hua ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Simultaneous Determination ◽  
Magnetic Separation ◽  
Simultaneous Detection ◽  
Fluorescence Immunoassay ◽  
Upconversion Fluorescence

The anti-thiamethoxam and anti-dextran monoclonal antibodies were prepared to develop a multicolor upconversion fluorescence immunoassay for the simultaneous determination of thiamethoxam (544 nm) and dextran (477 nm).

Exercise training prevents maturation-induced decrease in insulin sensitivity

1996 ◽  
Vol 80 (6) ◽  
pp. 1963-1967 ◽  
Author(s):  
N. Nakai ◽  
Y. Shimomura ◽  
N. Ohsaki ◽  
J. Sato ◽  
Y. Oshida ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Infusion Rate ◽  
Glucose Transporter ◽  
Euglycemic Clamp ◽  
Glut 4 ◽  
Hindlimb Muscle ◽  
Female Wistar Rats ◽  
Sensitivity Improvement

We examined the effects of exercise training initiated before maturation or after maturation on insulin sensitivity and glucose transporter GLUT-4 content in membrane fractions of skeletal muscle. Female Wistar rats (4 wk of age) were divided into sedentary and exercise-trained groups. At 12 wk of age, a subset of the trained animals (Tr) was killed along with a subset of sedentary controls (Sed). One-half of the remaining sedentary animals remained sedentary (Sed-Sed) while the other half began exercise training (Sed-Tr). The remaining rats in the original trained group continued to train (Tr-Tr). Euglycemic clamp (insulin infusion rate at 6 mU.kg body wt-1. min-1) was performed at 4, 12, and 27 wk. After euglycemic clamp in all animals except the 4-wk-old, hindlimb (gastrocnemius and part of quadriceps) muscles were removed for preparation of membrane fractions. In sedentary rats, glucose infusion rate (GIR) during euglycemic clamp was decreased from 15.9 mg.kg-1.min-1 at 4 wk of age to 9.8 mg.kg-1.min-1 at 12 wk of age and 9.1 mg.kg-1.min-1 at 27 wk of age. In exercise-trained rats, the GIR was not significantly decreased by maturation (at 12 wk) and further aging (at 27 wk). Initiation of exercise after maturation restored the GIR at 27 wk of age to the same levels as these for the corresponding exercise-trained rats. GLUT-4 content in plasma and intracellular membrane fractions of hindlimb muscle obtained just after euglycemic clamp showed the same trend as the results of GIR. These results suggest that exercise training prevented the maturation-induced decrease in insulin sensitivity. Improvement of insulin sensitivity caused by exercise training was attributed, at least in part, to the increase in insulin-sensitive GLUT-4 on the plasma membrane in skeletal muscle.

Sensitivity Improvement in Electrochemical Immunoassays Using Antibody Immobilized Magnetic Nanoparticles with a Clean ITO Working Electrode

2020 ◽  
Vol 14 (3) ◽  
pp. 308-316
Author(s):  
Sunga Song ◽  
Young Joo Kim ◽  
Hye-Lim Kang ◽  
Sumi Yoon ◽  
Dong-Ki Hong ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Working Electrode ◽  
Sensitivity Improvement ◽  
Electrochemical Immunoassays
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