Highly sensitive amperometric enzyme immunoassay for α-fetoprotein in human serum

Abstract A highly sensitive two-site sandwich ELISA measuring total proinsulin immunoreactive material in serum or plasma was developed. The assay was based on two monoclonal antibodies, an anti-C-peptide antibody bound to a microtest plate and a biotin-labeled anti-insulin antibody. The detection limit (3 SD above zero value) in buffer was 0.05 pmol/L, corresponding to 0.25 pmol/L in human serum (diluted 1:5). The linear calibrator range was 0.05-20 pmol/L. Interassay CVs were 4.7% at a median (range) of 2.3 pmol/L (1.4-2.8 pmol/L, n = 8), 6.7% at 5.1 pmol/L (3.3-8.0 pmol/L, n = 8), and 8.7% at 10.0 pmol/L (8-12 pmol/L, n = 10). Mean analytical recovery of added human proinsulin (hPI) (2, 5, and 10 pmol/L) to serum was 84% (range 68-128%, n = 9). Human insulin and human C-peptide did not cross-react at 5000 and 10,000 pmol/L, respectively. The four major proinsulin conversion intermediates reacted 65-99%: split(32-33)hPI 74%, des-(31,32)hPI 65%, split(65-66)hPI 78%, and des(64,65)hPI 99%. All serum values from 38 fasting healthy subjects were above the detection limit: median (range) 4.0 (2.1-12.6) pmol/L.

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Development of a highly sensitive and selective microplate chemiluminescence enzyme immunoassay for the determination of free thyroxine in human serum

International Journal of Biological Sciences ◽

10.7150/ijbs.3.274 ◽

2007 ◽

pp. 274-280 ◽

Cited By ~ 14

Author(s):

Xu Wang ◽

Hui Chen ◽

Jin-Ming Lin ◽

Xitang Ying

Keyword(s):

Human Serum ◽

Enzyme Immunoassay ◽

Free Thyroxine ◽

Highly Sensitive ◽

Chemiluminescence Enzyme Immunoassay

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A highly sensitive enzyme immunoassay of anti-insulin antibodies in human serum

Clinica Chimica Acta ◽

10.1016/0009-8981(87)90271-3 ◽

1987 ◽

Vol 168 (1) ◽

pp. 97-107 ◽

Cited By ~ 2

Author(s):

Takeyuki Kohno ◽

Eiji Ishikawa ◽

Satoru Sugiyama ◽

Masaki Kamano ◽

Hideshi Kuzuya ◽

...

Keyword(s):

Human Serum ◽

Enzyme Immunoassay ◽

Insulin Antibodies ◽

Highly Sensitive

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A Highly Sensitive Sandwich Enzyme Immunoassay for Insulin in Human Serum Developed Using Capybara Anti-Insulin Fab' -Horseradish Peroxidase Conjugate

Analytical Letters ◽

10.1080/00032718308069543 ◽

1983 ◽

Vol 16 (19) ◽

pp. 1509-1523 ◽

Cited By ~ 64

Author(s):

Masayoshi Imagawa ◽

Seiichi Hashida ◽

Eiji Ishikawa ◽

Hiroyuki Mori ◽

Chiharu Nakai ◽

...

Keyword(s):

Horseradish Peroxidase ◽

Human Serum ◽

Enzyme Immunoassay ◽

Highly Sensitive ◽

Sandwich Enzyme Immunoassay ◽

Peroxidase Conjugate

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Solid-phase enzyme immunoassay for serum ferritin.

Clinical Chemistry ◽

10.1093/clinchem/25.8.1426 ◽

1979 ◽

Vol 25 (8) ◽

pp. 1426-1431 ◽

Cited By ~ 22

Author(s):

S Anaokar ◽

P J Garry ◽

J C Standefer

Keyword(s):

Horseradish Peroxidase ◽

Human Serum ◽

Enzyme Immunoassay ◽

Serum Ferritin ◽

Solid Phase ◽

Highly Sensitive

Abstract We describe a solid-phase enzyme immunoassay for ferritin in human serum, with use of a horseradish peroxidase-labeled antibody and a highly sensitive chromogen, 2,2'-azino-di(3-ethyl-benzthiazoline-6-sulfonate). The assay requires only 10 microL of serum per assay, relatively less time and labor than other assys for ferritin, and as little as 10 pg of ferritin can be measured. We believe this assay offers a reliable alternative to radioimmunoassay for serum ferritin.

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A highly sensitive sandwich enzyme immunoassay of urinary growth hormone in children with short stature, Turner's syndrome, and simple obesity

Acta Endocrinologica ◽

10.1530/acta.0.1210513 ◽

1989 ◽

Vol 121 (4) ◽

pp. 513-519 ◽

Cited By ~ 6

Author(s):

Hiroshi Tomita ◽

Masamichi Ogawa ◽

Takashi Kamijo ◽

Osamu Mori ◽

Eiji Ishikawa ◽

...

Keyword(s):

Short Stature ◽

Enzyme Immunoassay ◽

Gh Deficiency ◽

Urine Samples ◽

Turner's Syndrome ◽

Turner’S Syndrome ◽

Highly Sensitive ◽

Significant Difference ◽

Simple Obesity ◽

Sandwich Enzyme Immunoassay

Abstract. GH values were determined by a highly sensitive sandwich enzyme immunoassay in the 1st morning and/or 24-h accumulated urine samples in 94 children (short stature 70, including 14 with complete GH deficiency, 9 with partial GH deficiency, and 47 with GH-normal short stature; Turner's syndrome, 10, and simple obesity, 14). GH values were also determined in the 2nd to 4th urine samples taken on the same day together with the 1st morning urine in 5 of them. GH values in the 1st morning urine correlated significantly with those of the 24-h urine and with serum peak and mean GH values during nocturnal sleep as a physiological GH secretion test. The 2nd to 4th urines had lower GH concentrations than the 1st morning urine. The GH value of the 1st morning urine in complete GH deficiency was significantly lower than those in GH-normal short stature, partial GH deficiency and Turner's syndrome. However, no significant difference was detected in urinary GH values between complete GH deficiency and simple obesity. We conclude that 1st morning urinary GH estimation may be useful for differentiation of complete GH deficiency from other causes of short stature, but may be difficult for the distinction between complete GH deficiency and obesity with normal GH secretory ability.

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Detection of Glucose in Human Serum Based on Silicon Dot Probe

Current Analytical Chemistry ◽

10.2174/1573411015666190702152331 ◽

2020 ◽

Vol 16 (6) ◽

pp. 744-752

Author(s):

Kuan Luo ◽

Xinyu Jiang

Keyword(s):

Quantum Dots ◽

Blood Glucose ◽

Human Serum ◽

Organic Dyes ◽

Limit Of Detection ◽

Fasting Blood Glucose ◽

Glucose Biosensor ◽

Metal Nanoclusters ◽

Glucose Levels ◽

Highly Sensitive

Background: Diabetes Mellitus (DM) is a major public metabolic disease that influences 366 million people in the world in 2011, and this number is predicted to rise to 552 million in 2030. DM is clinically diagnosed by a fasting blood glucose that is equal or greater than 7 mM. Therefore, the development of effective glucose biosensor has attracted extensive attention worldwide. Fluorescence- based strategies have sparked tremendous interest due to their rapid response, facile operation, and excellent sensitivity. Many fluorescent compounds have been employed for precise analysis of glucose, including quantum dots, noble metal nanoclusters, up-converting nanoparticles, organic dyes, and composite fluorescent microspheres. Silicon dot as promising quantum dots materials have received extensive attention, owing to their distinct advantages such as biocompatibility, low toxicity and high photostability. Methods: MnO2 nanosheets on the Si nanoparticles (NPs) surface serve as a quencher. Si NPs fluorescence can make a recovery by the addition of H2O2, which can reduce MnO2 to Mn2+, and the glucose can thus be monitored based on the enzymatic conversion of glucose by glucose oxidase to generate H2O2. Therefore, the glucose concentration can be derived by recording the fluorescence recovery spectra of the Si NPs. Results: This probe enabled selective detection of glucose with a linear range of 1-100 μg/mL and a limit of detection of 0.98 μg/mL. Compared with the commercial glucometer, this method showed favorable results and convincing reliability. Conclusion: We have developed a novel method based on MnO2 -nanosheet-modified Si NPs for rapid monitoring of blood glucose levels. By combining the highly sensitive H2O2/MnO2 reaction with the excellent photostability of Si NPs, a highly sensitive, selective, and cost-efficient sensing approach for glucose detection has been designed and applied to monitor glucose levels in human serum with satisfactory results.

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Highly sensitive and ratiometric luminescence sensing of heparin through templated cyanostilbene assemblies

The Analyst ◽

10.1039/d0an01808b ◽

2021 ◽

Author(s):

Shubhra Kanti Bhaumik ◽

Supratim Banerjee

Keyword(s):

Human Serum ◽

Cluster Formation ◽

Fluorometric Detection ◽

Aqueous Buffer ◽

Highly Sensitive

Heparin templated highly emissive cluster formation of di-cationic cyanostilbenes was utilized for the fluorometric detection of the polyanion in aqueous buffer, human serum and plasma.

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