scholarly journals Gradients of a Sandwich-structured Immunosensor Controlled Using Magnetized Masks for Determination of Human Serum Albumin Using Electrochemiluminescence

2021 ◽  
Author(s):  
Chun-Yao Huang ◽  
Chi-Jung Chang ◽  
Bohr-Ran Huang ◽  
Chien-Hsing Lu ◽  
jemkun chen
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Magnetic Beads ◽  
Limit Of Detection ◽  
High Reliability ◽  
Water Evaporation ◽  
Serum Samples ◽  
Dry Process ◽  
Physical Features

Abstract Background: Separation of macromolecules or particles from a colloid system to from gradient structure on the surface has been employed for biosensing systems, suggesting an enhancement of the chemical and physical features of particles. Performance of an electrochemiluminescence (ECL) immunosensor was employed to improve with a particle gradient.Results: Magnetic beads with silicon dioxide coating were adopted as nanocarriers for gradient manipulation and immobilized with the primary antibody. Cadmium telluride quantum dots (CdTe QDs) were coated with a layer of protein G for conjugation and orientation of secondary antibody as signal labels. ECL immunosensor gradients upon the electrode were formed by magnetolithography with magnetized nickel masks of column and stripe arrays at various scales. The immunosensor generally aggregated as island on the substrate through a dry process of water evaporation leading to a decrease of efficiency in the characteristic signals. Stripe arrays of magnetized nickel were designed to generate cylindrical magnetic flux on the substrate to improve the particle manipulation with the gradient. Various gradients of the sandwich-structured immunosensor substantially affected the electrochemical performance. Compared to the gradient-free immunosensor, the gradient of the immunosensor generated using the 3-μm-stripe array mask of magnetolithography enhanced the ECL intensity ~2.2 times. Conclusions: The results of quantification of human serum albumin (HSA) with the gradient immunosensor showed a broad linear range (15–420 ng mL−1), a low limit of detection (8 ng mL−1) and high reliability for HSA-spiked serum samples, indicating that the immunosensor gradient substantially enhances the performance of the ECL assay.

Monoclonal antibodies evaluated for use in a screening assay for conjugates of human serum albumin and pyridoxal 5'-phosphate.

1989 ◽  
Vol 35 (8) ◽  
pp. 1756-1760 ◽  
Author(s):  
B B Miller ◽  
W E Turner
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Human Serum Albumin ◽  
Human Serum ◽  
Limit Of Detection ◽  
Screening Method ◽  
Serum Samples ◽  
Screening Assay ◽  
Antibody Avidity ◽  
Negative Results

Abstract This enzyme immunoassay (EIA) was developed to measure pyridoxal 5'-phosphate bound to albumin (PLP-HSA) in human serum. The monoclonal antibody titer was 1:2000 and a sequential saturation analysis curve, prepared with samples containing from 10 to 1000 nmol/L, showed a 50% inhibition of antibody at 50 nmol of the conjugate per liter. The lower limit of detection for PLP-HSA was 10 nmol/L, a sensitivity 1000-fold greater than that for any potential interferent. When serum samples gave negative results in the assay, we compared the antigenicity of the principal sites for PLP binding on HSA. It was apparent that the preferred physiological site was not antigenic; however, three additional sites for PLP binding on HSA elicited comparable antibody avidity. This EIA is potentially quite sensitive and specific for PLP-HSA, but considerable additional effort is required to convert serum PLP to an HSA-bound form detectable in the assay, which limits its application as a screening method.

Automated Ligand Fishing Using Human Serum Albumin-Coated Magnetic Beads

2007 ◽  
Vol 79 (14) ◽  
pp. 5414-5417 ◽  
Author(s):  
R. Moaddel ◽  
M. P. Marszałł ◽  
F. Bighi ◽  
Q. Yang ◽  
X. Duan ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Magnetic Beads ◽  
Ligand Fishing

scholarly journals SARS-CoV-2 Spike protein binding of glycated serum albumin - its potential role in the pathogenesis of the COVID-19 clinical syndromes and bias towards individuals with pre-diabetes/type 2 diabetes & metabolic diseases.

2021 ◽  
Author(s):  
Jason K Iles ◽  
Raminta Zmuidinaite ◽  
Christoph Saddee ◽  
Anna Gardiner ◽  
Jonathan Lacy ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Immune Evasion ◽  
Magnetic Beads ◽  
Metabolic Diseases ◽  
Serum Proteins ◽  
Diabetes Type 2 ◽  
Spike Protein ◽  
Albumin Concentration

Since the immune response to SARS-CoV2 infection requires antibody recognition of the Spike protein, we used MagMix, a semi-automated magnetic rack to reproducibly isolate patient plasma proteins bound to a pre-fusion stabilised Spike and nucleocapsid proteins conjugated to magnetic beads. Once eluted, MALDI-ToF mass spectrometry identified a range of immunoglobulins, but also in Spike protein magnetic beads we found a high affinity for human serum albumin. Careful mass comparison revealed a preferential capture of AGE glycated human serum albumin by the pre-fusion Spike protein. The ability of bacteria and viruses to surround themselves with serum proteins is a recognised process of immune evasion. A lower serum albumin concentration is a reported feature of COVID-19 patients with severe symptoms and high probability of death. This binding preference of the Spike protein for AGE glycated serum albumin may contribute to immune evasion and influence the severity & pathology of SARS-COV2 towards acute respiratory distress. Thus contributing to the symptom severity bias and mortality risk for the elderly and those with (pre)diabetic and atherosclerotic/metabolic diseases who contract SARS-CoV2 infections.

scholarly journals QCM-based assay designs for human serum albumin

2021 ◽  
Author(s):  
Wisnu Arfian A. Sudjarwo ◽  
Mathias Thomas Dobler ◽  
Peter A. Lieberzeit
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Polymer Nanoparticles ◽  
Dependent Manner ◽  
Imprinted Polymer ◽  
Limit Of Quantification ◽  
Concentration Dependent Manner

AbstractSolid-phase synthesis is an elegant way to create molecularly imprinted polymer nanoparticles (nano-MIPs) comprising a single binding site, i.e. mimics of antibodies. When using human serum albumin (HSA) as the template, one achieves nano-MIPs with 53 ± 19 nm diameter, while non-imprinted polymer nanoparticles (nano-NIPs) reach 191 ± 96 nm. Fluorescence assays lead to Stern–Volmer plots revealing selective binding to HSA with selectivity factors of 1.2 compared to bovine serum albumin (BSA), 1.9 for lysozyme, and 4.1 for pepsin. Direct quartz crystal microbalance (QCM) assays confirm these results: nano-MIPs bind to HSA immobilized on QCM surfaces. This opens the way for competitive QCM-based assays for HSA: adding HSA to nanoparticle solutions indeed reduces binding to the QCM surfaces in a concentration-dependent manner. They achieve a limit of detection (LoD) of 80 nM and a limit of quantification (LoQ) of 244 nM. Furthermore, the assay shows recovery rates around 100% for HSA even in the presence of competing analytes.

Bilirubin binding by primary sites of human serum albumin, with suppression of secondary-site interference by use of a high salt concentration.

1980 ◽  
Vol 26 (1) ◽  
pp. 107-110 ◽  
Author(s):  
R B Rutkowski
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Secondary Site ◽  
Serum Samples ◽  
Nacl Concentration ◽  
Spectral Absorbance ◽  
Bilirubin Binding ◽  
Column Procedure ◽  
Site Binding

Abstract A high (2.0 mol/L) NaCl concentration apparently suppresses the secondary-site binding of bilirubin by human serum albumin. Thus if an excess of bilirubin is added to human serum albumin or to neonatal serum in buffer containing 0.1 mol of tris(hydroxymethyl)aminomethane and 2.0 mol of NaCl per liter (pH 7.5), and the bilirubin not bound to albumin is removed by treatment with calcium carbonate, the bilirubin binding reserve of primary binding sites can be estimated from direct measurement of spectral absorbance at 468 nm. Hemolysis and conjugated bilirubin apparently do not interfere. In a comparison study with serum samples from neonates the method gave results that generally agreed with those obtained by a commercially available Sephadex G-25 column procedure. In serum samples from adults the calculated unbound unconjugated bilirubin (free bilirubin) values derived by using binding reserves determined by the proposed method correlated well with the free bilirubin concentrations measured by a peroxidase method, but were only about one-half the amounts obtained by the peroxidase method.

Bilirubin binding by primary sites of human serum albumin, with suppression of secondary-site interference by use of a high salt concentration.

1980 ◽  
Vol 26 (1) ◽  
pp. 107-110
Author(s):  
R B Rutkowski
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Secondary Site ◽  
Serum Samples ◽  
Nacl Concentration ◽  
Spectral Absorbance ◽  
Bilirubin Binding ◽  
Column Procedure ◽  
Site Binding

Abstract A high (2.0 mol/L) NaCl concentration apparently suppresses the secondary-site binding of bilirubin by human serum albumin. Thus if an excess of bilirubin is added to human serum albumin or to neonatal serum in buffer containing 0.1 mol of tris(hydroxymethyl)aminomethane and 2.0 mol of NaCl per liter (pH 7.5), and the bilirubin not bound to albumin is removed by treatment with calcium carbonate, the bilirubin binding reserve of primary binding sites can be estimated from direct measurement of spectral absorbance at 468 nm. Hemolysis and conjugated bilirubin apparently do not interfere. In a comparison study with serum samples from neonates the method gave results that generally agreed with those obtained by a commercially available Sephadex G-25 column procedure. In serum samples from adults the calculated unbound unconjugated bilirubin (free bilirubin) values derived by using binding reserves determined by the proposed method correlated well with the free bilirubin concentrations measured by a peroxidase method, but were only about one-half the amounts obtained by the peroxidase method.

scholarly journals Design of Coelenterazine Analogue to Reveal Bioluminescent Reaction of Human Serum Albumin

2021 ◽  
Author(s):  
Ryo Nishihara ◽  
Kazuki Niwa ◽  
Tatsunosuke Tomita ◽  
Ryoji Kurita
Keyword(s):  
Quantitative Analysis ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Alkyl Chain ◽  
Light Emission ◽  
Enzymatic Oxidation ◽  
Luminescence Properties ◽  
Kinetic Properties ◽  
Serum Samples

This chapter describes the design of an imidazopyrazinone-type luciferin named as HuLumino1 by us and investigation of its luminescence properties. This luciferin was designed to generate bioluminescence by human serum albumin (HSA) rather than by luciferase derived from luminous organisms. HuLumino1 was developed by modifying a methoxy-terminated alkyl chain to the C-6 position and eliminating a benzyl group at the C-8 position of coelenterazine. To clarify the basis of light emission by HSA, the detailed kinetic properties of the HuLumino1/HSA pair were investigated using a calibrated luminometer. The enzymatic oxidation of HuLumino1 was observed only in the presence of HSA. Results of HSA quantification experiments using HuLumino1 agreed with less than 5% differences with those of enzyme-linked immunosorbent assays, suggesting HuLumino1 could be used for quantitative analysis of HSA levels in serum samples without any pretreatments. These results demonstrate the advantages of the coelenterazine analogue as a bioluminescence reagent to detect non-labeled proteins, which generally do not function as enzymes.

scholarly journals Development of a Novel ssDNA Sequence for a Glycated Human Serum Albumin and Construction of a Simple Aptasensor System Based on Reduced Graphene Oxide (rGO)

Biosensors ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 141
Author(s):  
A-Ru Kim ◽  
Yeongmi Choi ◽  
Sang-Heon Kim ◽  
Hyun-Seok Moon ◽  
Jae-Ho Ko ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Reduced Graphene Oxide ◽  
Limit Of Detection ◽  
Fluorescence Signal ◽  
Quenching Effect ◽  
High Affinity ◽  
Reduced Graphene

Diabetes is one of the top 10 global causes of death. About one in 11 global adults have diabetes. As the disease progresses, the mortality rate increases, and complications can develop. Thus, early detection and effective management of diabetes are especially important. Herein, we present a novel glycated human serum albumin (GHSA) aptamer, i.e., GABAS-01, which has high affinity and specificity. The aptamer was selected by reduced graphene oxide-based systematic evolution of ligands by exponential enrichement (rGO-based SELEX) against GHSA. After five rounds of selection through gradually harsher conditions, GABAS-01 with high affinity and specificity for the target was obtained. GABAS-01 was labeled by FAM at the 5′-end and characterized by measuring the recovery of a fluorescence signal that is the result of fluorescence quenching effect of rGO. As a result, GABAS-01 had low-nanomolar Kd values of 1.748 ± 0.227 nM and showed a low limit of detection of 16.40 μg/mL against GHSA. This result shows the potential application of GABAS-01 as an effective on-site detection probe of GHSA. In addition, these properties of GABAS-01 are expected to contribute to detection of GHSA in diagnostic fields.

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