#26547433 2015/12/07 To Up
Functionalized gold nanoclusters as fluorescent labels for immunoassays: Application to human serum immunoglobulin E determination.A quantitative immunoassay for the determination of immunoglobulin E (IgE) in human serum using gold nanoclusters (AuNCs) as fluorescent label was developed. Water soluble AuNCs were synthesized using lipoic acid and then thoroughly characterized. The obtained AuNCs have a particle size of 2.7 ± 0.1 nm and maximum fluorescence emission at 710 nm. The synthesized AuNCs showed very good stability of the fluorescent signal with light exposure and at neutral and slightly basic media. A covalent bioconjugation of these AuNCs with the desired antibody was carried out by the carbodiimide reaction. After due optimization of such bioconjugation reaction, a molar ratio 1:3 (antibody:AuNCs) was selected. The bioconjugate maintained an intense luminescence emission, slightly red-shifted as compared to the free AuNCs. Two typical immunoassay configurations, competitive and sandwich, were assayed and their performance for IgE determination critically compared. After the different immunoassay steps were accomplished, the fluorescence emission of the bioconjugate was measured. While the sandwich format provided a detection limit (DL) of 10 ng/mL and a linear range between 25 and 565 ng/mL of IgE, the competitive format revealed a DL of 0.2 ng/mL with a linear range between 0.3 and 7.1 ng/mL The applicability of the more sensitive competitive fluorescent immunoassay was assessed by successful analysis of the IgE in human serum and comparison of results with those from a commercial kit. The main advantages of the proposed AuNCs-based fluorimetric method include a low DL and a simple immunoassay protocol involving few reagents.
There is about (16597) Related Products to Functionalized gold nanoclusters as fluorescent labels for immunoassays: Application to human serum immunoglobulin E determination.immunoglobulin superfamil Human Killer cell immunog Fluorescent 100 bp DNA La Mouse Immunoglobulin E EL Bovine Immunoglobulin G,I Porcine secretory immunog Rabbit Anti-GPR78 Polyclo Hamster Complement Serum Hamster Complement Serum Mouse Anti-Parathyroid Ho anti-Human Serum Albumin EIA for Quantitative Dete
#27611475 2016/09/09 To Up
Size-controlled preparation of peroxidase-like graphene-gold nanoparticle hybrids for the visible detection of norovirus-like particles.A hybrid structure of graphene-gold nanoparticles (Grp-Au NPs) was designed as a new nanoprobe for colorimetric immunoassays. This hybrid structure was prepared using chloroauric acid, sodium formate and Grp flakes at room temperature. Au NPs attached strongly onto the Grp surface, and their size was controlled by varying the sodium formate concentration. The Raman intensity of the Grp-Au NP hybrids was significantly enhanced at 1567cm(-1) and 2730cm(-1) compared with those of pristine Grp because of the electronic interaction between Au NPs and Grp. The Grp-Au NPs with a hybrid structure catalyzed the oxidation of the peroxidase substrate 3,3,5,5-tetramethylbenzidine (TMB) with H2O2, developing a blue color in aqueous solution. This catalytic activity was utilized to detect norovirus-like particles (NoV-LPs) in human serum. The enhanced colorimetric response was monitored using Ab-conjugated-Grp-Au NPs and found to depend on the NoV-LP concentration, exhibiting a linear response from 100pg/mL to 10μg/mL. The limit of detection (LOD) of this proposed method was 92.7pg/mL, 112 times lower than that of a conventional enzyme-linked immunosorbent assay (ELISA). The sensitivity of this test was also 41 times greater than that of a commercial diagnostic kit. The selectivity of the Grp-Au NPs was tested with other viruses, and no color changes were observed. Therefore, the proposed system will facilitate the utilization of the intrinsic peroxidase-like activity of Grp-Au NPs in medical diagnostics. We believe that the engineered catalytic Grp-Au NP hybrids could find potential applications in the future development of biocatalysts and bioassays.
There is about (9592) Related Products to Size-controlled preparation of peroxidase-like graphene-gold nanoparticle hybrids for the visible detection of norovirus-like particles.Syringe pump can be contr MarkerGeneTM Live Cell Fl QuantiChrom™ Acetylchol EnzyChrom™ D-Lactate As EnzyChrom™ Acetylcholin QuantiChrom™ BCP Albumi EnzyChrom™ NAD NADH Ass EnzyChrom™ Catalase Ass EnzyChrom™ Lactose Assa EnzyChrom™ Pyruvate Ass EnzyChrom™ Fructose Ass Mouse Anti-Norovirus Caps
#10928685 2000/11/15 To Up
Acetyl- and pseudo-cholinesterase activities of plasma, erythrocytes, and whole blood in male beagle dogs using Ellman's assay.Organophosphate and carbamate ester insecticides, main causes of pesticide poisoning, inhibit cholinesterase (ChE) enzymes. The aim of this study was to measure and compare baseline values for pseudocholinesterase and acetylcholinesterase (AChE) enzyme activities of different blood fractions in the dog to aid in diagnosis of anticholinesterase poisoning. After collecting blood samples from 23 6-24-mo-old male beagle dogs, Ellman's colorimetric assay was run on plasma, red blood cells (RBC), and whole blood fractions prepared in triplicate. The procedure described in a commercially available kit was applied to plasma and RBC. Hemolyzed whole blood fractions (final dilution 1:8) avoided the time-consuming and laborious separation of plasma and RBC. In addition to the kit substrate acetylthiocholine (ASCh), we used butyrylthiocholine (BSCh) as substrate. Whatever the substrate, ChE activity was lower in RBC than in other blood preparations. It was higher when using ASCh rather than BSCh as substrate (mean IU/L+/-SD): 563+/-144 and 303+/-45 respectively, in contrast to plasma (1640+/-310 and 2510+/-450). Whole blood enzyme activity did not differ significantly according to substrate: ASCh, 1590+/-190; BSCh, 1620+/-250) with a 2 to 3% within-day coefficient of variation. Enzyme activity was significantly lower in dogs <1-y old. This study confirms the low ChE activity in dog RBC compared to other species and other blood fractions. It shows that using whole blood instead of separating RBC from plasma minimizes the variability of ChE activity in the hemoglobin-rich fraction.
There is about (19276) Related Products to Acetyl- and pseudo-cholinesterase activities of plasma, erythrocytes, and whole blood in male beagle dogs using Ellman's assay.Anti-Acetyl Cholinesteras Anti-Acetyl Cholinesteras Anti-Acetyl Cholinesteras Anti-Acetyl Cholinesteras Beagle Whole Blood 100ml Beagle Whole Blood 50ml K Beagle Whole Blood 50ml K Beagle Whole Blood 100ml Beagle Whole Blood 50ml N Beagle Whole Blood 50ml L Beagle Whole Blood 50ml N Beagle Whole Blood 50ml N
#18555983 2008/09/08 To Up
Advantages of the WRAIR whole blood cholinesterase assay: comparative analysis to the micro-Ellman, Test-mate ChE, and Michel (DeltapH) assays.Red blood cell AChE (RBC-AChE) and plasma BChE can be used as sensitive biomarkers to detect exposure to OP nerve agents, pesticides, and cholinergic drugs. In a comparative study, RBC-AChE and serum BChE activities in whole blood was obtained from forty seven healthy male and female human volunteers, and then exposed separately ex vivo to three OP nerve agents (soman (GD), sarin (GB) and VX) to generate a wide range of inhibition of AChE and BChE activity (up to 90% of control). These samples were measured using four different ChE assays: (i) colorimetric microEllman (using DTNB at 412 nm), (ii) Test-mate ChE field kit (also based on the Ellman assay), (iii) Michel (delta pH), and (iv) the Walter Reed Army Institute of Research Whole Blood (WRAIR WB) cholinesterase assay. The WRAIR assay is a modified Ellman method using DTP at 324 nm (which minimizes hemoglobin interference and improves sensitivity), and determines AChE and BChE in a small whole blood sample simultaneously. Scatter plots of RBC-AChE activities were determined using the WRAIR ChE assay versus the micro-Ellman, Test-mate and Michel after exposure to varying concentrations of soman, sarin and VX. Regression analyses yielded mostly linear relationships with high correlations (r2 = 0.83-0.93) for RBC-AChE values in the WRAIR assay compared to the alternate methods. For the plasma BChE measurements, individual human values were significantly more variable (as expected), resulting in lower correlations using WRAIR ChE versus the alternate assays (r2 values 0.5 - 0.6). To circumvent the limitations of simple correlation analysis, Bland and Altman analysis for comparing two independent measurement techniques was performed. For example, a Bland and Altman plot of the ratio of the WRAIR whole blood AChE and Michel AChE (plotted on the y-axis) vs. the average of the two methods (x-axis) shows that the majority of the individual AChE values are within +/- 1.96 S.D. of the mean difference, indicating that the two methods may be used interchangeably with a high degree of confidence. The WRAIR ChE assay can be thus be used as a reliable inter-conversion assay when comparing results from laboratory-based (Michel) and field-based (Test-mate ChE kit), which use different methodology and report in different units of AChE activity.
There is about (29128) Related Products to Advantages of the WRAIR whole blood cholinesterase assay: comparative analysis to the micro-Ellman, Test-mate ChE, and Michel (DeltapH) assays.EpiQuik Global Histone H3 EpiQuik Global Histone H3 Total Antioxidant Capacit Glutathione (GSH GSSG Tot Hydrogen Peroxide Assay K Ascorbic Acid Assay Kit10 ApoBrdU IHC DNA Fragmenta Phosphate Colorimetric As Glutathione Reductase Ass Endothelial Tube Formatio Fecal Occult Blood test s Troponin I test card, ser
#27899859 2016/11/30 To Up
Effect of N-Perfluorooctane on Hypoxia/Reoxygenation Injury in Human Umbilical Vein Endothelial Cells.This study investigated the effect of n-perfluorooctane (PFC) on hypoxia/reoxygenation (H/R) injury in human umbilical vein endothelial cells (HUVECs).
There is about (6121) Related Products to Effect of N-Perfluorooctane on Hypoxia/Reoxygenation Injury in Human Umbilical Vein Endothelial Cells.Human Umbilical Vein Endo GFP Expressing Human Umbi Mitochondria GFP Tag Huma RFP Expressing Human Umbi Plasma Membrane GFP Tag H Human Saphenous Vein Endo RFP Expressing Human Saph GFP Expressing Human Saph Mouse Anti-Human Endothel Human Cord Blood CD34+ Ce Rat Anti-Human Endothelia Human Iliac Artery Endoth
#18382788 2008/04/02 To Up
Study of oxidative stress in type 2 diabetic patients and its relationship with glycated hemoglobin.To evaluate the activity of antioxidant enzymes in diabetic patients and also to determine the correlation between hyperglycemia and lipid peroxidation.
There is about (25803) Related Products to Study of oxidative stress in type 2 diabetic patients and its relationship with glycated hemoglobin.8 Isoprostane oxidative s OXI TEK (Oxidative Stress DIABETIC DISEASES-Glycate DIABETIC DISEASES Glycate Transcription factors: O Albumin, Glycated Albumin, Glycated Antibod 8 OHdG ELISA Glycated Serum Protein (F Single Donor Human Diabet Single Donor Human Diabet Disease State Samples: Si
#9169060 1997/06/19 To Up
Simulated dermal contamination with capillary samples and field cholinesterase biomonitoring.The extensive international use of organophosphorus compounds (OP) results in numerous acute intoxications each year. OPs inhibit acetylcholinesterase, the enzyme responsible for breaking down the neurotransmitter acetylcholine. The World Health Organization recognizes cholinesterase (ChE) biomonitoring as a preventive measure against OP overexposure. The aim of this study was to determine if dermal OP contamination could interfere with current field ChE biomonitoring assays, which use a fingerstick blood sample. In this study we also sought to determine if high levels of a plasma enzyme, A-esterase, could protect ChE from inhibition by hydrolyzing environmentally generated oxons potentially present in a fingerstick sample. A heparinized venous blood sample was collected from a volunteer. Erythrocyte acetylcholinesterase (AChE) and plasma butyrylcholinesterase (PChE) activities were measured using a field-based colorimetric cholinesterase kit. ChE dose-response curves were constructed by allowing 10-microliters blood samples to contact environmentally realistic levels of OP thioate and oxon for 10 s. An inhibition threshold could not be established for PChE when exposed to oxon within the time necessary to perform a fingerstick analysis. AChE was also inhibited by trace amounts of oxon consistent with previously reported environmental levels. These findings suggest that the reliability of field-based biomonitoring results is limited if OP residues remain on a skin surface at the time of sample collection. A-esterase's role in protecting ChE activity was investigated using capillary and venous blood from 30 unexposed individuals. Baseline ChE activities were measured, as were individual A-esterase activities using paraoxon, diazoxon, and phenylacetate as substrates. Results were then compared to ChE activities measured after 10 s of contact with an environmentally realistic amount of OP, containing 1% oxon. Both ChE activities were significantly inhibited, with capillary values being significantly more inhibited than their venous counterparts. However, no protective effect could be associated between the degree of A-esterase activity and the subsequent level of ChE inhibition observed in an individual's blood. These results suggest that (1) if there is any uncertainty about OP skin contamination, venous blood would be a more appropriate specimen to employ when using field ChE biomonitoring kits--it is collected in larger volumes and has essentially no direct contact to dermal surfaces; and (2) A-esterase activity demonstrates no protective effect against ChE inhibition upon a blood droplet's brief contact with an OP residue containing traces of oxon.
There is about (21521) Related Products to Simulated dermal contamination with capillary samples and field cholinesterase biomonitoring.Cholinesterase, Kinetic, Anti-Acetyl Cholinesteras Anti-Acetyl Cholinesteras Human Dermal Microvascula RFP Expressing Human Neon Anti-Acetyl Cholinesteras GFP Expressing Human Neon Anti-Acetyl Cholinesteras Human Dermal Lymphatic Mi GFP Expressing Human Derm Homogenizer for 24 sample MiRNA Northern Blot Assay
#8496669 1993/06/23 To Up
Release of small amounts of free fatty acids from human adipocytes as determined by chemiluminescence.A semiautomatic luminometric method for determination of small amounts of free fatty acids (FFA) released from human adipocytes in vitro is described. Bovine serum albumin (BSA) is used as acceptor of free fatty acids in the incubation medium of isolated fat cells. The assay involves pretreatment with the detergent sodium dodecyl sulfate (SDS) to liberate the free fatty acids from the bovine serum albumin before activation by acyl-CoA synthetase (ACS) (EC 126.96.36.199). This is followed by oxidation of the resulting thioesters by acyl-CoA oxidase (ACO). The H2O2 formed is subsequently measured in a horseradish peroxidase (HRP) (EC 188.8.131.52)-catalyzed luminol reaction. The assay is linear in the interval of 0.01-1 nmol in the cuvette corresponding to 2-200 microM in the sample, and 25 samples are automatically assayed in the luminometer within 75 min. FFA release could easily be studied in a small incubation volume (200 microliters) of very diluted (10(4) cells/ml) human adipocyte suspensions. Samples (25 microliters) containing 0.25% BSA from incubates of adipose tissue cells did not interfere with the standard curve. The analytical interference from different factors that could be used in studies of lipolysis was investigated. No interference was observed up to the following concentrations: 5 microM epinephrine, 5 microM norepinephrine, 80 microM isoproterenol, 1 mM insulin, 2.5 mM propranolol, 5 mM phentolamine, and 5 microM ascorbate. Results obtained with the present assay were highly correlated (r = 0.997) with those obtained by a 260-times less sensitive spectrophotometric kit method.(ABSTRACT TRUNCATED AT 250 WORDS)
There is about (21543) Related Products to Release of small amounts of free fatty acids from human adipocytes as determined by chemiluminescence.Triglyceride Assay Kit Li EnzyChrom™ Free Fatty A EnzyChrom™ Free Fatty A BSA, Fatty Acid-Free(Assa Free Fatty Acid Quantific Fatty acid free heat sho BSA, Fatty Acid-Free(Assa BSA, Fatty Acid-Free (Ass Fatty acid free heat shoc Fatty acid free heat sho Fatty acid free heat sho Fatty acid free heat sho
#27023678 2016/03/30 To Up
Thiobarbituric Acid-Reactive Substances: Markers of an Acute Episode and a Late Stage of Bipolar Disorder.Lowered antioxidant defense systems and increased oxidative stress are implicated in bipolar disorders (BD). Early and late stages of BD may present different biological features (including the level of oxidative stress) and may therefore require different treatment strategies. The aim of this study was to analyze serum levels of lipid peroxidation [measured as thiobarbituric acid-reactive substances (TBARS), a derivative of malondialdehyde] in BD patients at various stages and phases of the illness and compare their TBARS levels with those of healthy controls.
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#28192489 2017/02/13 To Up
Honokiol induces reactive oxygen species-mediated apoptosis in Candida albicans through mitochondrial dysfunction.To investigate the effects of honokiol on induction of reactive oxygen species (ROS), antioxidant defense systems, mitochondrial dysfunction, and apoptosis in Candida albicans.
There is about (25138) Related Products to Honokiol induces reactive oxygen species-mediated apoptosis in Candida albicans through mitochondrial dysfunction.MarkerGeneTM Live Cell Fl Rabbit Anti- Candida albi Rabbit Anti- Candida albi Mouse Anti-Candida albica Rabbit Anti- Candida albi Candida albicans antibody Honokiol Honokiol Creatine kinase (mitochon mitochondrial carrier pro Pig translocase of outer ATP synthase H+ transport
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