scholarly journals Automated gold particle quantification of immunogold labeled micrographs

2017 ◽  
Vol 286 ◽  
pp. 31-37 ◽  
Author(s):  
Rune Enger
Keyword(s):  
Gold Particle ◽  
Particle Quantification

The Shadow Widths of Very Small Particles are Formed Independently of the Metal Cap Build Up on the Particle

1981 ◽  
Vol 39 ◽  
pp. 568-569
Author(s):  
George C. Ruben
Keyword(s):  
Gold Particle ◽  
Film Surface ◽  
Small Particles ◽  
Geometric Process ◽  
Metal Free ◽  
Shadow Area

The formation of shadows behind small particles has been thought to be a geometric process (GP) where the metal cap build up on the particle creates a shadow width the same size as or larger than the particle. This GP cannot explain why gold particle shadow widths are generally larger than the gold particle and may have no appreciable metal cap build up (fig. 1). Ruben and Telford have suggested that particle shadow widths are formed by the width dependent deflection of shadow metal (SM) lateral to and infront of the particle. The trajectory of the deflected SM is determined by the incoming shadow angle (45°). Since there can be up to 1.4 times (at 45°) more SM directly striking the particle than the film surface, a ridge of metal nuclei lateral to and infront of the particle can be formed. This ridge in turn can prevent some SM from directly landing in the metal free shadow area. However, the SM that does land in the shadow area (not blocked by the particle or its ridge) does not stick and apparently surface migrates into the SM film behind the particle.

scholarly journals Laser Superficial Fusion of Gold Nanoparticles with PEEK Polymer for Cardiovascular Application

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 971
Author(s):  
Oktawian Bialas ◽  
Mateusz Lis ◽  
Anna Woźniak ◽  
Marcin Adamiak
Keyword(s):  
Particle Size ◽  
Laser Beam ◽  
Gold Particle ◽  
Laser Power ◽  
Biomedical Application ◽  
Parameters Optimization ◽  
Size Reduction ◽  
Particle Size Reduction ◽  
Nano Gold ◽  
Gold Particle Size

This paper analyses the possibility of obtaining surface-infused nano gold particles with the polyether ether ketone (PEEK) using picosecond laser treatment. To fuse particles into polymer, the raw surface of PEEK was sputtered with 99.99% Au and micromachined by an A-355 laser device for gold particle size reduction. Biomimetic pattern and parameters optimization were key properties of the design for biomedical application. The structures were investigated by employing surface topography in the presence of micron and sub-micron features. The energy of the laser beam stating the presence of polymer bond thermalisation with remelting due to high temperature was also taken into the account. The process was suited to avoid intensive surface modification that could compromise the mechanical properties of fragile cardiovascular devices. The initial material analysis was conducted by power–depth dependence using confocal microscopy. The evaluation of gold particle size reduction was performed with scanning electron microscopy (SEM), secondary electron (SE) and quadrant backscatter electron detector (QBSD) and energy dispersive spectroscopy (EDS) analysis. The visibility of the constituted coating was checked by a commercial grade X-ray that is commonly used in hospitals. Attempts to reduce deposited gold coating to the size of Au nanoparticles (Au NPs) and to fuse them into the groove using a laser beam have been successfully completed. The relationship between the laser power and the characteristics of the particles remaining in the laser irradiation area has been established. A significant increase in quantity was achieved using laser power with a minimum power of 15 mW. The obtained results allowed for the continuation of the pilot study for augmented research and material properties analysis.

Time-resolved probing of the acoustic field radiated by a single submicron gold particle

2011 ◽  
Author(s):  
Yannick Guillet ◽  
Bertrand Audoin ◽  
Mélanie Ferrie ◽  
Serge Ravaine
Keyword(s):  
Acoustic Field ◽  
Gold Particle ◽  
Time Resolved

A method for determining the periodicity of a troponin component in isolated insect flight muscle thin filaments by gold/Fab labelling

1992 ◽  
Vol 101 (3) ◽  
pp. 503-508
Author(s):  
R. Newman ◽  
G.W. Butcher ◽  
B. Bullard ◽  
K.R. Leonard
Keyword(s):  
Gold Particle ◽  
Colloidal Gold ◽  
Striated Muscle ◽  
Flight Muscle ◽  
Insect Flight ◽  
Insect Flight Muscle ◽  
Fab Fragment ◽  
Thin Filaments ◽  
Gold Particles ◽  
Almost All

Insect flight muscle has a large component (Tn-H) in the tropomyosin-troponin complex that is not present in vertebrate striated muscle thin filaments. Tn-H is shown by gold/Fab labelling to be present at regular intervals in insect flight muscle thin filaments. The Fab fragment of a monoclonal antibody to Tn-H was conjugated directly with colloidal gold and this probe used to label isolated thin filaments from the flight muscle of Lethocerus indicus (water bug). The distribution of gold particles seen in electron microscope images of negatively stained thin filaments was analysed to show that the probe bound to sites having a periodicity of approximately 40 nm, which is the expected value for the tropomyosin-troponin repeat. Conjugates of Fab with colloidal gold particles of 3 nm diameter labelled almost all sites. Conjugates with gold particles of 5 nm and 10 nm diameter labelled less efficiently (70% and 30%, respectively) but analysis of the distribution of inter-particle intervals among a number of filaments again gave the same fundamental spacing of 40 nm. The error in the measurements (standard deviation approximately +/− 4.2 for 5 nm gold/Fab) is less than earlier estimates for the size of the gold/Fab complex. Measurements on gold/Fab in negative stain suggest that the bound Fab contributes a shell about 2 nm in thickness around the gold particle. The radius of the probe (about 4.5 nm for 5 nm gold/Fab) would then be consistent with the value of error found. The size of the probe suggests that the gold particle binds to the side of the Fab molecule, rather close to the antibody combining site. The potential resolution of the technique may thus be better than originally expected.

scholarly journals Volumetric registration of magnetic nanoparticles for optimization of quantitative immunochromatographic assays for detection of small molecules

2018 ◽  
Vol 185 ◽  
pp. 10006 ◽  
Author(s):  
Natalia V. Guteneva ◽  
Sergey L. Znoyko ◽  
Alexey V. Orlov ◽  
Maxim P. Nikitin ◽  
Petr I. Nikitin
Keyword(s):  
Magnetic Nanoparticles ◽  
Small Molecules ◽  
Optical Methods ◽  
Magnetic Method ◽  
Label Free ◽  
Spectral Correlation ◽  
Entire Volume ◽  
Specificity And Sensitivity ◽  
Particle Quantification

Precise quantitative and highly sensitive detection of small molecules (haptens) is highly demanded in medicine, food quality control, in vitro diagnostics, criminalistics, environmental monitoring, etc. In the present work, the magnetic method of particle quantification and the optical methods of spectral correlation and spectral phase interferometry complement each other for optimization of a quantitative assay for measuring concentrations of small molecules. The assay employs magnetic nanoparticles as labels in rapid immunochromatographic format. The approach was demonstrated with fluorescein as a model molecule. The interferometric label-free biosensors were employed for selection of optimal reagents that produced high specificity and sensitivity. The method of magnetic particle quantification counted the magnetic labels over the entire volume of the immunochromatographic membrane to provide their distribution along the test strip. Such distribution was used for optimization of such parameters as concentrations of the used reagents and of antibody immobilized on the labels, amount of the labels and conjugates of haptens with protein carriers to realize the advanced quantitative immunochromatographic assay.

scholarly journals Review of Post-embedding Immunogold Methods for the Study of Neuronal Structures

2021 ◽  
Vol 15 ◽  
Author(s):  
Ronald S. Petralia ◽  
Ya-Xian Wang
Keyword(s):  
Thin Section ◽  
Gold Particle ◽  
Freeze Substitution ◽  
Particle Sizes ◽  
Neuronal Function ◽  
Double Labeling ◽  
Thin Sections ◽  
Transmission Electron ◽  
Functional Localization ◽  
Neuronal Tissues

The post-embedding immunogold (PI) technique for immunolabeling of neuronal tissues utilizing standard thin-section transmission electron microscopy (TEM) continues to be a prime method for understanding the functional localization of key proteins in neuronal function. Its main advantages over other immunolabeling methods for thin-section TEM are (1) fairly accurate and quantifiable localization of proteins in cells; (2) double-labeling of sections using two gold particle sizes; and (3) the ability to perform multiple labeling for different proteins by using adjacent sections. Here we first review in detail a common method for PI of neuronal tissues. This method has two major parts. First, we describe the freeze-substitution embedding method: cryoprotected tissue is frozen in liquid propane via plunge-freezing, and is placed in a freeze-substitution instrument in which the tissue is embedded in Lowicryl at low temperatures. We highlight important aspects of freeze-substitution embedding. Then we outline how thin sections of embedded tissue on grids are labeled with a primary antibody and a secondary gold particle-conjugated antibody, and the particular problems encountered in TEM of PI-labeled sections. In the Discussion, we compare our method both to earlier PI methods and to more recent PI methods used by other laboratories. We also compare TEM immunolabeling using PI vs. various pre-embedding immunolabeling methods, especially relating to neuronal tissue.

Cellular Trajectories of Peptide-Modified Gold Particle Complexes:  Comparison of Nuclear Localization Signals and Peptide Transduction Domains

2004 ◽  
Vol 15 (3) ◽  
pp. 482-490 ◽  
Author(s):  
Alexander G. Tkachenko ◽  
Huan Xie ◽  
Yanli Liu ◽  
Donna Coleman ◽  
Joseph Ryan ◽  
...  
Keyword(s):  
Nuclear Localization ◽  
Gold Particle ◽  
Nuclear Localization Signals ◽  
Peptide Transduction
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