scholarly journals A new method for transfer of polyethylene glycol-embedded tissue sections to silanated slides for immunocytochemistry.

1991 ◽  
Vol 39 (4) ◽  
pp. 537-540 ◽  
Author(s):  
K X Gao ◽  
J D Godkin
Keyword(s):  
Polyethylene Glycol ◽  
Colloidal Gold ◽  
Cell Structure ◽  
High Sensitivity ◽  
Antigen Detection ◽  
New Method ◽  
Retinol Binding Protein ◽  
Tissue Sections ◽  
Glass Slides ◽  
Structural Preservation

Polyethylene glycol (PEG) is an excellent embedding medium for immunohistochemical studies. It provides structural preservation superior to frozen sections and increased sensitivity of antigen detection compared with paraffin sections. One limitation of PEG embedment is that PEG sections are difficult to handle and adhere poorly to glass slides. Here we present a simple and effective method for embedding tissues in PEG and transferring the resultant sections onto silanated glass slides. In addition, a method for silver enhanced colloidal gold immunostaining was combined with common dye staining to demonstrate the excellent structure preservation and sensitive antigen detection. Bovine chorionic membrane was fixed with Bouin's fixative, embedded in polyethylene glycol (PEG) 1500, cut into 5-microns sections, flattened over agarose blocks (10 x 10 x 2 mm3), and blotted onto Digene silanated slides. Slides were then washed in PBS, which removed the PEG and agarose blocks. Tissue sections were immunocytochemically stained with dilute antiserum raised in a rabbit against purified bovine placental retinol binding protein (bpRBP). Sections were washed and incubated with 1-nm colloidal gold-labeled goat anti-rabbit IgG. The immunogold particles were enhanced by silver staining (IGSS). Specimens were observed and photographed with an Olympus epipolarization microscope. The new method offered excellent morphological preservation of cell structure and the epipolarization microscopy provided high sensitivity for detection of specific immunogold-silver particles.

scholarly journals In situ hybridization using PEG-embedded tissue and riboprobes: increased cellular detail coupled with high sensitivity.

1989 ◽  
Vol 37 (3) ◽  
pp. 389-393 ◽  
Author(s):  
D F Clayton ◽  
A Alvarez-Buylla
Keyword(s):  
In Situ Hybridization ◽  
High Sensitivity ◽  
Cresyl Violet ◽  
High Signal ◽  
Tissue Sections ◽  
Glass Slides ◽  
Cresyl Violet Staining ◽  
Rna Probes ◽  
Hybridization Protocol

We describe a procedure for preparing tissue sections by embedding in polyethylene glycol for subsequent in situ hybridization analysis using single-stranded RNA probes. Improved tissue morphology is obtained as compared to frozen sections, and the embedding procedure is milder and faster than paraffin embedding. Sections as thin as 2 microns are readily cut from PEG-embedded brain tissue. A simplified hybridization protocol (Clayton et al.: Neuron 1:249, 1988) supports the detection of even low-abundance brain mRNAs (less than or equal to 10(-4) fractional mRNA mass). By employing high stringency washes in place of ribonuclease treatment after hybridization, cell RNA is retained for cresyl violet staining, and high signal:noise ratios are achieved. Solutions to problems with section mounting and adherence to glass slides are presented. The combination of improved morphology, high signal levels, and relative simplicity should make this procedure useful in a variety of applications.

scholarly journals Light microscopic visualization of colloidal gold on resin-embedded tissue.

1983 ◽  
Vol 31 (12) ◽  
pp. 1394-1398 ◽  
Author(s):  
G Danscher ◽  
J O Nörgaard
Keyword(s):  
Colloidal Gold ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Metallic Silver ◽  
Frozen Sections ◽  
Electron Microscopic ◽  
Tissue Sections ◽  
Amplification Method ◽  
Glass Slides ◽  
Present Technique

RNase labeled with colloidal gold was used as a model for the present technique evolved for the light microscopic localization of gold-labeled substances in semithin resin-embedded sections. Tissue sections placed on glass slides were treated with the gold-enzyme complex and subsequently exposed to a photographic developed containing silver lactate. During the development gold particles are encapsulated in growing shells of metallic silver and gradually made visible in the light microscope. The amplification method can be applied to paraffin-embedded and frozen sections as well. This technique may prove useful as a supplement to studies utilizing colloidal gold or silver as markers normally used at the electron microscopic level.

scholarly journals Clinical Application of a New SARS-CoV-2 Antigen Detection Kit (Colloidal Gold) in the Detection of COVID-19

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 995
Author(s):  
Evangelos Terpos ◽  
Ioannis Ntanasis-Stathopoulos ◽  
Miha Skvarč
Keyword(s):  
Sensitivity And Specificity ◽  
Colloidal Gold ◽  
False Negative ◽  
High Sensitivity ◽  
Antigen Detection ◽  
Disease Course ◽  
Ct Value ◽  
Nasal Swabs ◽  
Precise Diagnosis ◽  
Positive Cycle

The precise diagnosis of COVID-19 is of outmost importance in order to effectively treat patients and prevent SARS-CoV-2 transmission. Herein, we evaluated the sensitivity and specificity of the COVID-19 Antigen Detection Kit (Colloidal Gold—CG) compared with PCR in nasopharyngeal and nasal samples. A total of 114 positive and 244 negative nasopharyngeal specimens confirmed by PCR were used in this comparative study. When the PCR positive Cycle Threshold (Ct) value was ≤25, CG sensitivity was 100%. When the PCR positive Ct value was ≤33, CG sensitivity was 99%. When the PCR positive Ct value was ≤40, CG sensitivity was 89.47%. Regarding nasal swabs, a total of 109 positive and 250 negative specimens confirmed by PCR were used. When the PCR positive Ct value was ≤25, CG sensitivity was 100%. When the PCR positive Ct value was ≤33, CG sensitivity was 96.12%. When the PCR positive Ct value was ≤37, CG sensitivity was 91.74%. Specificity was above 99% regardless of the Ct value of PCR positivity for both nasopharyngeal and nasal specimens. Overall, the CG showed high sensitivity and specificity when the PCR Ct value was less than 33. Therefore, CG can be used for screening early in the disease course. Confirmatory PCR is essential when a false negative result is suspected.

The Application of Protein A-Gold Immunocytochemistry to Studies of Protein Secretion

1985 ◽  
Vol 43 ◽  
pp. 426-429
Author(s):  
George H. Herbener ◽  
Antonio Nanci ◽  
Moise Bendayan
Keyword(s):  
Tissue Section ◽  
Colloidal Gold ◽  
Unit Area ◽  
Protein A ◽  
Extracellular Proteins ◽  
Gold Complex ◽  
Second Step ◽  
Igg Antibodies ◽  
Tissue Sections ◽  
Antigenic Sites

Protein A-gold immunocytochemistry is a two-step, post-embedding labeling procedure which may be applied to tissue sections to localize intra- and extracellular proteins. The key requisite for immunocytochemistry is the availability of the appropriate antibody to react in an immune response with the antigenic sites on the protein of interest. During the second step, protein A-gold complex is reacted with the antibody. This is a non- specific reaction in that protein A will combine with most IgG antibodies. The ‘label’ visualized in the electron microscope is colloidal gold. Since labeling is restricted to the surface of the tissue section and since colloidal gold is particulate, labeling density, i.e., the number of gold particles per unit area of tissue section, may be quantitated with ease and accuracy.

Lubricant compatibility of FKM seals in synthetic oils

2019 ◽  
Vol 72 (5) ◽  
pp. 557-565
Author(s):  
Dilek Bulut ◽  
Tatjana Krups ◽  
Gerhard Poll ◽  
Ulrich Giese
Keyword(s):  
Polyethylene Glycol ◽  
Design Methodology ◽  
Elevated Temperatures ◽  
Failure Mechanisms ◽  
Standard Test ◽  
New Method ◽  
Static Tests ◽  
Content Type ◽  
Lip Seals ◽  
First Results

Purpose Elastomer seals are used in many applications. They are exposed to lubricants and additives at elevated temperatures, as well as mechanical stresses. They can only provide good sealing function when they have resistance to those factors. There are many elastomer-lubricant compatibility tests based on DIN ISO 1817 in industry. However, they are insufficient and costly. Correlations between the tests and the applications are inadequate. The purpose of this study is investigating lubricant compatibility of fluoroelastomers (FKM) seals in polyethylene-glycol (PG)- and polyalphaolefin (PAO)- based synthetic oils and developing a methodology to predict seal service life. Design/methodology/approach A new compatibility test which is more sufficient in terms of time and cost was developed and compared with a standard test, currently used in industry. Compatibility of FKM radial lip seals with PG- and PAO-based synthetic oils with different additives was investigated chemically and dynamically. Failure mechanisms were examined. Findings The new method and the Freudenberg Flender Test FB 73 11 008 showed similar results concerning damages and similar tendencies regarding wear. The additive imidazole derivative was the most critical. Static tests give indications of possible chemically active additives, but alone they are insufficient to simulate the dynamic applications. Originality/value The paper describes a new method to investigate elastomer-lubricant compatibility and gives first results with a variety of lubricants.

Quantification of Tire-Tread Particles Using Extractable Organic Zinc as Tracer

1999 ◽  
Vol 72 (5) ◽  
pp. 969-977 ◽  
Author(s):  
Patrik Fauser ◽  
Jens Christian Tjell ◽  
Hans Mosbaek ◽  
Kim Pilegaard
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Environmental Samples ◽  
High Sensitivity ◽  
Absorption Spectrometry ◽  
Soil Samples ◽  
New Method ◽  
Organic Zinc

Abstract A method for identifying and quantifying tire-tread particles in the environment has been developed. It is based on the measurement of extractable organic zinc. The high sensitivity of atomic absorption spectrometry (AAS) with a heated graphite atomizer (HGA) permits assessment of submilligram amounts of tire debris in environmental samples. The analysis is performed on aerosol and soil samples. This new method is more accurate and faster than the previously reported IR method.

Blood Biomarkers to Differentiate Ischemic and Hemorrhagic Strokes Might Allow Prehospital Thrombolysis

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000011742
Author(s):  
Alejandro Bustamante ◽  
Anna Penalba ◽  
Cyrille Orset ◽  
Leire Azurmendi ◽  
Víctor Llombart ◽  
...  
Keyword(s):  
Point Of Care ◽  
High Sensitivity ◽  
Retinol Binding Protein ◽  
Hospital Treatment ◽  
Glial Fibrillary Acid Protein ◽  
Blood Biomarkers ◽  
Retinol Binding Protein 4 ◽  
Biomarker Panel ◽  
Stroke Mimics ◽  
Suspected Stroke

Objective:We aimed to validate a panel of blood biomarkers to differentiate between ischemic stroke (IS) and intracerebral hemorrhage (ICH) in patients with suspected stroke.Methods:Patients with suspected stroke admitted within 4.5 hours after onset were enrolled. Blood samples were collected at hospital admission. Glial fibrillary acid protein (GFAP), retinol binding protein 4 (RBP-4), N-terminal pro B-type natriuretic peptide (NT-proBNP) and endostatin were measured by immunoassays. Cut-off points were obtained for 100% specificity for IS. A high-sensitivity assay to measure GFAP and rapid point-of-care tests (POCTs) to measure RBP-4 and NT-proBNP were used in subsets of patients. Biomarker panels were evaluated in another cohort of 62 stroke mimics.Results:A total of 189 patients (154 IS and 35 ICH) were enrolled. IS patients had higher RBP-4, NT-proBNP and endostatin and lower GFAP levels than ICH patients. The best biomarker combination for the identification of IS was RBP-4+NT-proBNP, which was able to identify 29.7% of IS patients with 100% specificity. In the subset of patients for whom GFAP was measured with the high-sensitivity assay, RBP-4, NT-proBNP and GFAP identified 51.5% of IS patients with 100% specificity. When stroke mimics were included, specificities were reduced to 98.4 and 96.8%, respectively. POCTs of RBP-4 and NT-proBNP showed results similar results to those of conventional ELISAs.Conclusions:A biomarker panel including RBP-4, NT-proBNP and GFAP provided moderate but potentially useful sensitivity rates at 100% specificity for IS diagnosis. If confirmed in future studies, this strategy might allow pre-hospital treatment in selected patients.Classification of Evidence:This study provides Class I evidence that a biomarker panel including RBP-4, NT-proBNP and GFAP distinguishes IS from ICH with moderate accuracy.==========

scholarly journals Development and Performance verification of colloidal gold labeled SARS-CoV-2 antigen detection method for routine popular screening of COVID-19 with clinical samples in Poland and China

2021 ◽  
Author(s):  
Chuanxiang Guo ◽  
Li Yao ◽  
Fengling Chen ◽  
Chao Zhang ◽  
Wei Chen
Keyword(s):  
Predictive Value ◽  
Colloidal Gold ◽  
Detection Method ◽  
Age Distribution ◽  
Antigen Detection ◽  
Lateral Flow ◽  
Rapid Screening ◽  
Clinical Samples ◽  
Lateral Flow Strip ◽  
And Performance

In this research, we have constructed and optimized the colloidal gold labeled lateral flow strip (LFS) for rapid detection of antigen of SARS-CoV-2 and rapid screening of COVID-19. Based on the constructed and optimized colloidal gold lateral flow strip, the parameters of the LFS have been well evaluated with the clinical samples in the professional labs. The screening performance have also been evaluated from the aspects including the CT values, age distribution and onset of symptoms. Finally, based on the detection results of 420 clinical samples, the LFS can achieve the screening of COVID-19 with the positive percentage agreement (PPA, sensitivity), negative percent agreement (NPA, specificity), the positive predictive value (PPV) and the negative predictive value (NPV) of 96.8%, 100%, 100% and 96.6%, respectively, indicating the powerful potential for practical screening applications in pandemic control. Of great significance, this developed SARS-CoV-2 antigen detection method has also been successfully utilized for screening of delta-variant of SARS-CoV-2.

Sign in / Sign up

Export Citation Format

Share Document