scholarly journals Development of a High-Throughput Automated Analyzer Using Biochip Array Technology

2005 ◽  
Vol 51 (7) ◽  
pp. 1165-1176 ◽  
Author(s):  
Stephen P FitzGerald ◽  
John V Lamont ◽  
Robert I McConnell ◽  
El O Benchikh
Keyword(s):  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Simultaneous Detection ◽  
Test Results ◽  
Assay Procedure ◽  
Assay Performance ◽  
Array Technology ◽  
Surface Contact Angle ◽  
Commercial Method ◽  
Processing Techniques

Abstract Background: Use of protein array technology over conventional assay methods has advantages that include simultaneous detection of multiple analytes, reduction in sample and reagent volumes, and high output of test results. The susceptibility of ligands to denaturation, however, has impeded production of a stable, reproducible biochip platform, limiting most array assays to manual or, at most, semiautomated processing techniques. Such limitations may be overcome by novel biochip fabrication procedures. Methods: After selection of a suitable biochip substrate, biochip surfaces were chemically modified and assessed to enable optimization of biochip fabrication procedures for different test panels. The assay procedure was then automated on a dedicated instrument, and assay performance was determined for a panel of cytokine markers. Assay results were then compared with a commercial method for measurement of cytokine markers. Results: Secondary ion mass spectrometry and x-ray photoelectron spectroscopy demonstrated appropriate and reproducible modification of the biochip surface. Contact-angle studies also confirmed generation of hydrophobic surfaces that enabled containment of droplets for fabrication of discrete test regions. Automation of the biochip assays on a dedicated instrument produced excellent cytokine marker performance with intra- and interassay imprecision <10% for most analytes. Comparison studies showed good agreement with other methods (r = 0.95–0.99) for cytokines. Conclusion: Performance data from this automated biochip array analyzer provide evidence that it is now possible to produce stable and reproducible biochips for output of more than 2000 test results per hour.

Robustness Testing of the xMAP Food Allergen Detection Assay: A Multiplex Assay for the Simultaneous Detection of Food Allergens

2020 ◽  
Vol 83 (6) ◽  
pp. 1050-1056 ◽  
Author(s):  
PRASAD RALLABHANDI ◽  
CHUNG Y. CHO ◽  
WILLIAM L. NOWATZKE ◽  
KERRY G. OLIVER ◽  
ERIC A. E. GARBER
Keyword(s):  
Food Allergen ◽  
Incubation Temperature ◽  
Simultaneous Detection ◽  
Multiplex Assay ◽  
Food Allergens ◽  
Assay Procedure ◽  
Extraction Buffer ◽  
Detection Assay ◽  
Assay Performance ◽  
Allergen Detection

ABSTRACT The xMAP food allergen detection assay (xMAP FADA) can simultaneously detect 15 analytes (14 food allergens plus gluten) in one analysis. The xMAP FADA typically employs two antibody bead sets per analyte, providing built-in confirmation that is not available with other antibody-based assays. Before an analytical method can be used, its reliability must be assessed when conditions of the assay procedure are altered. This study was conducted to determine the effects on assay performance associated with changes in incubation temperature, amounts of the antibody bead cocktail, and concentrations of detection antibody and β-mercaptoethanol in the reduced-denatured extraction buffer. The analysis of buffered-detergent extracts revealed lower responses at 22°C than at 37°C, but temperature had no effect on the analysis of reduced-denatured extracts. Changes in β-mercaptoethanol and detection antibody concentrations had an effect on the detection of only milk in the reduced-denatured extracts. A slight change in the measured bead count was observed when one-fourth of the bead cocktail was used, and a large decrease in the bead count was noted when one-eighth of the recommended amount was used, but this number (≥25) was still sufficient to provide reliable results. Overall, the xMAP FADA was very robust to changes in the assay procedure, which may inadvertently occur. HIGHLIGHTS

scholarly journals Wear Resistance Improvement of Cemented Tungsten Carbide Deep-Hole Drills after Ion Implantation

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 239
Author(s):  
Dmitrij Morozow ◽  
Marek Barlak ◽  
Zbigniew Werner ◽  
Marcin Pisarek ◽  
Piotr Konarski ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Tungsten Carbide ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Carbon Layer ◽  
Hole Drilling ◽  
Deep Hole ◽  
Tungsten Nitrides ◽  
Lubrication Effect ◽  
Secondary Ion

The paper is dedicated to the lifetime prolongation of the tools designed for deep-hole drilling. Among available methods, an ion implantation process was used to improve the durability of tungsten carbide (WC)-Co guide pads. Nitrogen fluencies of 3 × 1017 cm−2, 4 × 1017 cm−2 and 5 × 1017 cm−2 were applied, and scanning electron microscope (SEM) observations, energy dispersive spectroscopy (EDS) analyses, X-ray photoelectron spectroscopy (XPS) and Secondary Ion Mass Spectrometry (SIMS) measurements were performed for both nonimplanted and implanted tools. The durability tests of nonimplanted and the modified tools were performed in industrial conditions. The durability of implanted guide pads was above 2.5 times more than nonimplanted ones in the best case, presumably due to the presence of a carbon-rich layer and extremely hard tungsten nitrides. The achieved effect may be attributed to the dissociation of tungsten carbide phase and to the lubrication effect. The latter was due to the presence of pure carbon layer with a thickness of a few dozen nanometers. Notably, this layer was formed at a temperature of 200 °C, much smaller than in previously reported research, which makes the findings even more valuable from economic and environmental perspectives.

Interaction of Bovine Serum Albumin and Lysozyme with Stainless Steel Studied by Time-of-Flight Secondary Ion Mass Spectrometry and X-ray Photoelectron Spectroscopy

Langmuir ◽  
2012 ◽  
Vol 28 (47) ◽  
pp. 16306-16317 ◽  
Author(s):  
Yolanda S. Hedberg ◽  
Manuela S. Killian ◽  
Eva Blomberg ◽  
Sannakaisa Virtanen ◽  
Patrik Schmuki ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Stainless Steel ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Photoelectron Spectroscopy ◽  
Bovine Serum ◽  
Secondary Ion Mass Spectrometry ◽  
Time Of Flight ◽  
X Ray ◽  
Secondary Ion

Chromium implantation in silica glass

1996 ◽  
Vol 11 (1) ◽  
pp. 229-235 ◽  
Author(s):  
E. Cattaruzza ◽  
R. Bertoncello ◽  
F. Trivillin ◽  
P. Mazzoldi ◽  
G. Battaglin ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Photoelectron Spectroscopy ◽  
Silica Glass ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Secondary Ion Mass Spectrometry ◽  
Rutherford Backscattering Spectrometry ◽  
X Ray ◽  
Chromium Silicide ◽  
Secondary Ion

Silica glass was implanted with chromium at the energy of 35 and 160 keV and at fluences varying from 1 × 1016 to 11 × 1016 ions cm−2. In a set of chromium-implanted samples significant amounts of carbon were detected. Samples were characterized by x-ray photoelectron spectroscopy, x-ray-excited Auger electron spectroscopy, secondary ion mass spectrometry, and Rutherford backscattering spectrometry. Chromium silicide and chromium oxide compounds were observed; the presence of carbon in the implanted layers induces the further formation of chromium carbide species. Thermodynamic considerations applied to the investigated systems supply indications in agreement with the experimental evidences.

Investigation of Contaminants in Single Wafer Wet Cleaning Using Isopropyl Alcohol

2021 ◽  
Vol 314 ◽  
pp. 23-28
Author(s):  
Seungjun Oh ◽  
Sunyoung Lee ◽  
Heehwan Kim ◽  
Donggeon Kwak ◽  
Chulwoo Bae ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Isopropyl Alcohol ◽  
Secondary Ion Mass Spectrometry ◽  
Oxidation Reactions ◽  
X Ray ◽  
Technological Control ◽  
Technological Developments ◽  
Ultra Trace ◽  
Ethylene Tetrafluoroethylene ◽  
Secondary Ion

Technological control over ultra-trace level contaminants is important for semiconductor development. Despite technological developments, defects remain in the single wafer wet cleaning process. In this paper, the source of the contamination is explained via trace analytical methods. Fluorine resin materials of polytetrafluoroethylene (PTFE) and ethylene tetrafluoroethylene (ETFE) are commonly used in semiconductor equipment. Isopropyl alcohol (IPA) oxidation reactions occur at high temperature below the boiling point due to impurities. IPA changed to different alcohol forms from gas chromatography (GCMS) analysis. The oxygen concentration in the X-ray photoelectron spectroscopy (XPS) results increased and formed new bonds in IPA with fluorine resin. These reactions confirmed that cations were a catalyst from the time-of-flight secondary ion mass spectrometry (TOF-SIMS) results. Representative ions were Fe+, K+, and Na+ with different concentrations for each material.

Enterohemorrhagic Escherichia coli Colony Check Assay for the Identification of Serogroups O26, O45, O103, O111, O121, O145, and O157 Colonies Isolated on Plating Media

2014 ◽  
Vol 77 (7) ◽  
pp. 1212-1218 ◽  
Author(s):  
BURTON BLAIS ◽  
MYLÈNE DESCHÊNES ◽  
GEORGE HUSZCZYNSKI ◽  
MARTINE GAUTHIER
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
High Throughput Screening ◽  
Enterohemorrhagic Escherichia Coli ◽  
Test Results ◽  
Bacterial Strains ◽  
Enrichment Broth ◽  
Substrate Solution ◽  
E Coli ◽  
Assay Performance

A simple immunoenzymatic enterohemorrhagic Escherichia coli (EHEC) colony check (ECC) assay was developed for the presumptive identification of priority EHEC colonies isolated on plating media from enrichment broth cultures of foods. With this approach, lipopolysaccharide extracted from a colony is spotted on the grid of a polymyxin-coated polyester cloth strip, and bound E. coli serogroup O26, O45, O103, O111, O121, O145, and O157 antigens are subsequently detected by sequential reactions with a pool of commercially available peroxidase-conjugated goat antibodies and tetramethylbenzidine substrate solution. Each strip can accommodate up to 15 colonies, and test results are available within 30 min. Assay performance was verified using colonies from a total of 73 target EHEC isolates covering the range of designated priority serogroups (all of which were reactive), 41 nontarget E. coli isolates including several nontarget Shiga toxin–producing E. coli serogroups (all unreactive), and 33 non–E. coli strains (all unreactive except two bacterial strains possessing O-antigenic structures in common with those of the priority EHEC). The ECC assay was reactive with target colonies grown on several types of selective and nonselective plating media designed for their cultivation. These results support the use of the ECC assay for high-throughput screening of colonies isolated on plating media for detecting priority EHEC strains in foods.

Multiwalled Carbon Nanotubes Covered with Cobalt (II) Phthalocyanine by In Situ Synthesis and its Electrochemical Sensing Performance towards DA and UA

2014 ◽  
Vol 809-810 ◽  
pp. 43-52
Author(s):  
Hua Hua Wang ◽  
Nan Li ◽  
Kai Li ◽  
Yuan Bu ◽  
Wen Le Dai ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Simultaneous Detection ◽  
Thick Layer ◽  
Electrochemical Sensing ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Platinum Particles

Multiwalled carbon nanotubes (MWCNTs) as an excellent supporter covered with a thick layer of cobalt phthalocyanine (CoPc) were prepared by in-situ synthesis. Platinum particles were adopted to enhance the conductivity of CoPc-MWCNTs. The final nanocomposite Pt-CoPc-MWCNTs was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Strong aromatic π-π stacking between MWCNTs and CoPc made CoPc in-situ forming on MWCNTs. With homogeneous thickness of CoPc covered on the MWCNTs and Pt particles equally distributed, the nanocomposite was used as electrocatalyst. The electrochemical properties of the composite got researched by casting the dispersion of Pt-CoPc-MWCNTs on the glassy carbon electrode. Compared with other modified electrodes, Pt-CoPc-MWCNTs/GC electrode exhibited excellent electrochemical activity towards dopamine (DA) and uric acid (UA). Linear responses for DA and UA were obtained in the ranges of 5 to 170 μM and 5 to 100 μM, and limits of detection were 2.6 and 1.4 μM (S/N= 3), respectively. Simultaneous detection of DA and UA in the presence of ascorbic acid (AA) also displayed selective property, with no interference to each other.

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