A Simple, Quick One-step ELISA Assay for the Determination of Complex Plasma Factor XIII (A2B2)

SummaryA new highly sensitive sandwich ELISA assay was developed for the determination of plasma factor XIII (FXIII). Plasma FXIII is a tetrameric complex of two types of subunits (A2B2). A biotinylated monoclonal capture-antibody against the B-subunit and a peroxidase-labelled monoclonal tag-antibody against the A-subunit were added to the plasma dilution and the amount of the complex attached to streptavidincoated microplate was quantitated by measuring peroxidase activity. Only the tetrameric plasma FXIII reacted in the assay, non-complexed A or B subunits showed no reaction. The assay is linear up-to 40 µg/L of FXIII in the assay mixture. It is a quick one-step assay which can be performed within two hours. At normal and low FXIII concentration within batch reproducibility was 2.0% and 3.3%, day to day variation was 5.5% and 8.7%, respectively. Its high sensitivity allows reliable measurement at FXIII concentrations below 1% of normal average. Plasma samples can be stored for the assay at –20° C for at least one month. Plasma levels of healthy individuals were normally distributed and no gender difference was observed. A reference interval of 14-28 mg/L (67-133%) was established.

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72 A new highly sensitive rapid sandwich ELISA assay for the determination of blood coagulation factor XIII in human plasma

Fibrinolysis and Proteolysis ◽

10.1016/s0268-9499(98)80101-x ◽

1998 ◽

Vol 12 ◽

pp. 26

Keyword(s):

Human Plasma ◽

Blood Coagulation ◽

Factor Xiii ◽

Sandwich Elisa ◽

Coagulation Factor ◽

Elisa Assay ◽

Coagulation Factor Xiii ◽

Highly Sensitive ◽

Sandwich Elisa Assay

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Serum Neuregulin-1β as a Biomarker of Cardiovascular Fitness

The Open Biomarkers Journal ◽

10.2174/1875318300902010001 ◽

2009 ◽

Vol 2 (1) ◽

pp. 1-5 ◽

Cited By ~ 19

Author(s):

Vaibhav Moondra ◽

Satyam Sarma ◽

Tracy Buxton ◽

Radwan Safa ◽

Gregory Cote ◽

...

Keyword(s):

Physical Activity ◽

Skeletal Muscle ◽

Healthy Subjects ◽

Sandwich Elisa ◽

Bicycle Ergometer ◽

Cardiovascular Fitness ◽

Elisa Assay ◽

Healthy Men ◽

Sandwich Elisa Assay ◽

Cardio Respiratory Fitness

Purpose: Neuregulins (NRG) are growth factors that bind to receptors of the erbB family, and are known to mediate a number of processes involved in diverse tissues. Neuregulin-1β is expressed in skeletal muscle and is activated by exercise. We hypothesized that NRG-1β might circulate in the bloodstream and increase as a consequence of physical activity. A study was conducted in healthy subjects to determine if NRG-1β is immunodetectable in human serum, and if so whether levels relate acutely or chronically to exercise. Methods: Nine healthy men underwent three bouts of exercise of varying degrees of intensity on a bicycle ergometer over a period of three weeks. Cardio-respiratory fitness was determined by measurement of maximal oxygen uptake (VO2max). Serum was sampled prior to and immediately after each session (up to 30 minutes post) and serum NRG-1ß was quantified utilizing an indirect sandwich ELISA assay developed in our lab. Results: Across subjects, mean serum NRG-1β levels ranged from 32 ng/mL to 473 ng/mL. Individual subjects showed relatively stable levels during the study period that did not change acutely after exercise. Serum NRG-1β demonstrated a positive correlation with VO2max (r2=0.49, p =.044). Conclusions: These preliminary observations suggest that at least in healthy men, serum NRG-1β is an indicator of cardio- respiratory fitness and does not change acutely with exercise.

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Val34Leu polymorphism of plasma factor XIII: biochemistry and epidemiology in familial thrombophilia

Blood ◽

10.1182/blood.v96.7.2479 ◽

2000 ◽

Vol 96 (7) ◽

pp. 2479-2486 ◽

Cited By ~ 87

Author(s):

István Balogh ◽

Gabriella Szôke ◽

Levente Kárpáti ◽

Ulla Wartiovaara ◽

Éva Katona ◽

...

Keyword(s):

Protective Effect ◽

Venous Thrombosis ◽

Factor Xiii ◽

Coagulation Factor ◽

Wild Type ◽

Thrombin Cleavage ◽

Plasma Factor ◽

Thrombin Activation ◽

A Subunit ◽

The Mean

Abstract Val34Leu polymorphism of the A subunit of coagulation factor XIII (FXIII-A) is located in the activation peptide (AP) just 3 amino acids away from the thrombin cleavage site. This mutation has been associated with a protective effect against occlusive arterial diseases and venous thrombosis; however, its biochemical consequences have not been explored. In the current study it was demonstrated that the intracellular stability and the plasma concentration of FXIII of different Val34Leu genotypes are identical, which suggests that there is no difference in the rate of synthesis and externalization of wild-type and mutant FXIII-A. In contrast, the release of AP by thrombin from the Leu34 allele proceeded significantly faster than from its wild-type Val34 counterpart. By molecular modeling larger interaction energy was calculated between the Leu34 variant and the respective domains of thrombin than between the Val34 variant and thrombin. In agreement with these findings, the activation of mutant plasma FXIII by thrombin was faster and required less thrombin than that of the wild-type variant. Full thrombin activation of purified plasma FXIII of different genotypes, however, resulted in identical specific transglutaminase activities. Similarly, the mean specific FXIII activity in the plasma was the same in the groups with wild-type, heterozygous, and homozygous variants. Faster activation of the Leu34 allele hardly could be associated with its presumed protective effect against venous thrombosis. No such protective effect was observed in a large group of patients with familial thrombophilia.

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Sensitive electrochemical determination of dopamine and uric acid using AuNPs(EDAS)–rGO nanocomposites

Analytical Methods ◽

10.1039/c6ay00335d ◽

2016 ◽

Vol 8 (22) ◽

pp. 4379-4390 ◽

Cited By ~ 15

Author(s):

Victor Vinoth ◽

Jerry J. Wu ◽

Sambandam Anandan

Keyword(s):

Uric Acid ◽

High Sensitivity ◽

Electrochemical Determination ◽

Synthesis Process ◽

Potential Candidate ◽

Sonochemical Synthesis ◽

One Step ◽

Sensing Application ◽

Electro Catalytic Activity

AuNPs(EDAS) – rGO nanocomposites were prepared by a facile one step sonochemical synthesis process. Here, EDAS acts as an interlinker for anchoring gold on rGO and it also acts both as a reducing agent and a stabilizing agent. The AuNPs(EDAS) – rGO nanocomposites show excellent electro-catalytic activity towards oxidation of DA and UA. The AuNPs(EDAS) – rGO nanocomposites exhibit low detection limits, high sensitivity, it could be a potential candidate for sensing application and in biosensor technology in the future.

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Monoclonal Antibodies to Sea Cucumber Polysaccharide and Their Use in a Sandwich ELISA Assay

Hybridoma ◽

10.1089/hyb.2011.0025 ◽

2011 ◽

Vol 30 (4) ◽

pp. 381-385 ◽

Cited By ~ 2

Author(s):

Junjun Wang ◽

Hu Zhao ◽

Ying Zheng ◽

Wei Liu ◽

Hua Zhou ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Sea Cucumber ◽

Sandwich Elisa ◽

Elisa Assay ◽

Sandwich Elisa Assay

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A Photometric Assay for Blood Coagulation Factor XIII

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648185 ◽

1991 ◽

Vol 65 (05) ◽

pp. 535-540 ◽

Cited By ~ 82

Author(s):

Karl Fickenscher ◽

Angela Aab ◽

Werner Stüber

Keyword(s):

Factor Xiii ◽

Coagulation Factor ◽

Photometric Determination ◽

Peptide Substrate ◽

Normal Range ◽

Step Procedure ◽

Healthy Donors ◽

One Step ◽

Aggregation Inhibitor

SummaryAn assay for a direct photometric determination of F XIII in untreated and undiluted plasma was developed. In a one-step procedure F XIII is activated by thrombin and Ca2+ and crosslinks glycine-ethylester to a specific glutamine containing peptide substrate. The released ammonia is incorporated into α-keto-glutarate by glutamate dehydrogenase, and the NADH consumption of this reaction is measured photometrically at 340 nm. NADH-consumption is directly proportional to the F XIII activity. Fibrin polymerization and the corresponding turbidity is avoided by the use of a fibrin aggregation inhibitor.The procedure is rapid and simple and enables to measure within the range of 0 to 150% F XIII. It can be performed with automated analyzers as well as with common photometric equipment.The normal range of F XIII activity in 167 healthy donors was determined to be 70 to 140%.

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The Effect Of Plasmin On Factor XIII (Fibrin Stabilizing Factor)

10.1055/s-0038-1652712 ◽

1981 ◽

Author(s):

D M Rider ◽

J M McDonagh

Keyword(s):

Factor Xiii ◽

Activate Factor ◽

Polyacrylamide Gels ◽

Clotting Factors ◽

Human Fibrinogen ◽

Platelet Factor ◽

Plasma Factor ◽

Before And After ◽

A Subunit ◽

Almost All

The action of plasmin on several blood clotting factors has been studied; however, controversy exists concerning the effect of plasmin on factor XIII. Factor XIII was purified from plasma and platelets and then exposed to plasmin for up to 6 hours. Plasmin to factor XIII ratios ranged from 0.03-0.1 casein units plasmin per mg factor XIII. These plasmin levels exhibited strong proteolytic activities against B-casein and purified human fibrinogen Following incubation of factor XIII (activated and unactivated) with plasmin the mixtures were electrophoresed on 7% SDS-polyacrylamide gels. The factor XIII preparations were assayed for 14C-putrescine incorporating activity before and after exposure to plasmin. Platelet factor XIII was,labeled With 125Iodine and lableled a subunit (activated and unactivated) was exposed to plalmin for up to 2 hours. These mixtures were electrophoresed on 12.5% Urea-SDS Polyacrylamide gels and a radioactivity profile was determined for each gel.Following extensive exposure to Plasmin the relative molecular weights of the factor XIII subunits (a, a* and b)remained constant and almost all (90-100%) of the 14C-put-rescine incorporating activity was recovered. The radio-activity profiles of the gels of 125I-labeled platelet factor XIII were identical before and after incubation with plasmin. Plasmin did not activate factor XIII in the assay system nor did factor XIII inactivate plasmin by crosslinking it. These experiments indicate that plasmin does not activate or degrade factor XIII and that the b subunit of plasma factor XIII plays no role in protecting the a subunit from the action of plasmin.

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Biological Activity Test of Dendrobium Huoshanense and Its Application in the Detection of Environmental Pollutant Phenols

Science of Advanced Materials ◽

10.1166/sam.2021.4012 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1205-1214

Author(s):

Yujuan Wang ◽

Jun Dai ◽

Peipei Wei ◽

Yongping Cai ◽

Bangxing Han

Keyword(s):

Quantum Dots ◽

Hydrothermal Reaction ◽

High Sensitivity ◽

Carbon Quantum Dots ◽

Environmental Pollutant ◽

One Step ◽

New Type ◽

Filtration Effect ◽

Dendrobium Huoshanense

ABSTRACTIn this research, a new type of carbon quantum dot was prepared from Dendrobium huoshanense via one-step hydrothermal reaction at 200 °C for 6 h. The as-derived carbon quantum dots exhibited good fluorescence properties, with quantum yield of 23.57%. The extraction and determination of Dendrobium huoshanense enzymes activity were performed for different incubation times to study the theoretical reference for the dynamic changes of the main enzyme activity in the process of Dendrobium huoshanense growth and the solid processing industry. The results demonstrated that Dendrobium huoshanense was a low toxic carbon source material. Moreover, the prepared carbon quantum dots exhibited high sensitivity for the detection of nonylphenol, allowing a range of linear response of 0.5–50 µM (R2 = 0.9997). The detection limit was a slow as 95.32 nM. These results indicated that fluorescence internal filtration effect influenced nonylphenol-induced quenching of the Dendrobium huoshanense-carbon quantum dots fluorescence. The Dendrobium huoshanense-carbon quantum dots were successfully used to track nonylphenol in environmental samples. Therefore, their exploitation offers a promising approach for environmental pollutant detection.

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