scholarly journals QUANTITATIVE FLUORESCENCE MICROSCOPY: FLUORESCENT ANTIBODY AUTOMATIC SCANNING TECHNIQUES

1966 ◽  
Vol 14 (3) ◽  
pp. 260-273 ◽  
Author(s):  
H. P. MANSBERG ◽  
J. KUSNETZ
Keyword(s):  
Fluorescent Antibody ◽  
Spectral Characteristics ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Background Level ◽  
Fluorescein Isothiocyanate ◽  
Image Plane ◽  
Light Sources ◽  
Close Proximity ◽  
Quantitative Fluorescence

The application of microscanning techniques to the detection, classification and counting of fluorescence-tagged microorganisms presents unique and somewhat more severe optical and photometric problems than those encountered in absorption type microscanning. Low fluorescence emission, autofluorescence of optics, filters and specimen mounting media and the close proximity of the excitation and emission wavelengths of typical fluorochromes impose severe limitations on sensitivity and maximum scanning rates. By the use of bright field illumination, liquid dye immersion filters, and careful matching of light source and filter spectral characteristics to those of the fluorochromes, fluorescence output was increased 10-100 times with negligible increase in background level. The effectiveness of a number of light sources filters and phototubes in producing maximal signals from fluorescein isothiocyanate-tagged microorganisms in an experimental fluorescence microscanner are compared. Proper selection produced increases in sensitivity of more than 10 times the initial sensitivity obtained with standard fluorescence microscopes and illuminators. Image plane, object plane and flying spot scanning techniques are compared as to their suitability for fluorescence microscanning. Practical scanner designs are illustrated. A consideration of the advantages of laser excitation of fluorochromes indicates that in addition to greatly simplifying filtering problems, a 102 increase in irradiance can be expected. The possibility of differential diagnosis based upon two color fluorescence discrimination is explored. Overlapping emission spectra presents the major difficulties in such a system. An experimental two color fluorescence microscanner and the optical and electronic techniques employed for the discrimination of overlapping color spectra is described.

The biogenesis of the cyanellae of cyanophora paradoxa . I. Polypeptide composition of the cyanellae

1989 ◽  
Vol 238 (1290) ◽  
pp. 53-72 ◽  
Keyword(s):  
Spectral Characteristics ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Staining Procedure ◽  
Cyanophora Paradoxa ◽  
Polypeptide Composition ◽  
Ps Ii ◽  
Photochemical Activities ◽  
Molecular Masses ◽  
Ps Ii Core Complexes

Based on polypeptide separation, protein purification and immunoblotting techniques using heterologous antibodies, we have been able to identify several photosynthetically important polypeptide components of the cyanellae of Cyanophora paradoxa . Cytochrome c -552 and ferredoxin have been purified to electrophoretic homogeneity and exhibit apparent molecular masses of 10.5 and 9.0 kDa, respectively. Cytochrome c -552 has an isoelectric point of pH 4.2±0.1. Plastocyanin was immunologically and spectrally undetectable even in cells grown in the presence of Cu 2+ . Polypeptides for cytochromes f , b -6 and c -552 have been located in electrophoretically resolved thylakoid samples by using the TMBZ-staining procedure. Intact phycobilisomes have been purified and characterized with respect to polypeptide composition and absorption and emission spectra. Photosystems I and II have been isolated and characterized with respect to their photochemical activities, spectral characteristics and polypeptide composition. Photochemically active PS I complexes fluoresce maximally at 720 nm at 77 K and comprise five polypeptide subunits resolved under denaturing conditions with apparent molecular masses of 66, 21, 18, 14 and 11 kDa. PS II core complexes mediate light-dependent 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU)-sensitive electron transfer between 1,5-diphenylcarbazide (DPC) and 2,6-dichlorophenolindophenol (DPIP) at rates of 140–200 μmol h -1 mg -1 chlorophyll. These complexes exhibit absorption maxima at 436 and 673 nm and show fluorescence emission maxima at 685 and 695 nm at 77 K. Rubisco was separated by two-dimensional electrophoresis and immunologically characterized.

scholarly journals Fluorescence properties of free and protein bound fluorescein dyes. I. Macrospectrofluorometric measurements.

1978 ◽  
Vol 26 (4) ◽  
pp. 277-283 ◽  
Author(s):  
K Schauenstein ◽  
E Schauenstein ◽  
G Wick
Keyword(s):  
Blue Light ◽  
Fluorescence Intensity ◽  
Gamma Globulin ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Sharp Decrease ◽  
Fluorescein Isothiocyanate ◽  
Fluorescence Properties ◽  
Sodium Fluorescein ◽  
Uv Excitation

Excitation and emission properties of fluorescein derivatives were studied macrofluorometrically. Measurements were performed with solutions of various concentrations (0.07-100 microgram/ml) of free sodium fluorescein prepared from fluorescein diacetate (FDA), fluorescein isothiocyanate (FITC) and FITC bound to rabbit gamma-globulin. Both excitation and emission spectra as well as fluorescence intensities at constant excitation/emission wavelengths (496/515 nm) were recorded. The findings indicate that (1) FDA gives about twice the fluorescence intensity compared to equal concentrations of FITC. (2) The fluorescence properties of FITC upon excitation with blue light (lambda = 496 nm) are only slightly altered by the conjugation to rabbit gamma-globulin. (3) Considerable quenching due to conjugation could, however, be shown to occur upon UV excitation (lambda = 340 nm). (4) Fluorescence emission excited by visible blue light (496 nm) increases linearly to dye concentration in a range of 0.07-2.5 microgram/ml. Beginning at 5 microgram/ml (10-(5) M/1) all three compounds show a sharp decrease of fluorescence intensity with further increasing concentration. Practical aspects of these data for the immunofluorescence method are discussed.

Tandem scanning confocal light microscopy as compared with x-ray diffraction for characterizing the behavior of clays in fluid-saturated petroleum reservoir rock

1989 ◽  
Vol 47 ◽  
pp. 148-149
Author(s):  
C.J. Stuart ◽  
B.E. Viani ◽  
J. Walker ◽  
T.H. Levesque
Keyword(s):  
Light Microscopy ◽  
Image Plane ◽  
Reservoir Rock ◽  
Depth Of Field ◽  
Objective Lens ◽  
Scanning System ◽  
Light Sources ◽  
Petroleum Reservoir ◽  
Image Recording ◽  
Scan Speed

Many techniques of imaging used to characterize petroleum reservoir rocks are applied to dehydrated specimens. In order to directly study behavior of fines in reservoir rock at conditions similar to those found in-situ these materials need to be characterized in a fluid saturated state.Standard light microscopy can be used on wet specimens but depth of field and focus cannot be obtained; by using the Tandem Scanning Confocal Microscope (TSM) images can be produced from thin focused layers with high contrast and resolution. Optical sectioning and extended focus images are then produced with the microscope. The TSM uses reflected light, bulk specimens, and wet samples as opposed to thin section analysis used in standard light microscopy. The TSM also has additional advantages: the high scan speed, the ability to use a variety of light sources to produce real color images, and the simple, small size scanning system. The TSM has frame rates in excess of normal TV rates with many more lines of resolution. This is accomplished by incorporating a method of parallel image scanning and detection. The parallel scanning in the TSM is accomplished by means of multiple apertures in a disk which is positioned in the intermediate image plane of the objective lens. Thousands of apertures are distributed in an annulus, so that as the disk is spun, the specimen is illuminated simultaneously by a large number of scanning beams with uniform illumination. The high frame speeds greatly simplify the task of image recording since any of the normally used devices such as photographic cameras, normal or low light TV cameras, VCR or optical disks can be used without modification. Any frame store device compatible with a standard TV camera may be used to digitize TSM images.

The Influence Of The Led Luminaires Electrical Parameters On Their Correlated Colour Temperature During Operation Mode

2020 ◽  
pp. 89-96
Author(s):  
Sergei S. Kapitonov ◽  
Alexei S. Vinokurov ◽  
Sergei V. Prytkov ◽  
Sergei Yu. Grigorovich ◽  
Anastasia V. Kapitonova ◽  
...  
Keyword(s):  
Operation Mode ◽  
Light Sources ◽  
Electrical Parameters ◽  
Colour Temperature ◽  
Radiation Spectra ◽  
Service Period ◽  
Close Proximity ◽  
Definition Of ◽  
Comprehensive Study

The article describes the results of comprehensive study aiming at increase of quality of LED luminaires and definition of the nature of changes in their correlated colour temperature (CCT) in the course of operation. Dependences of CCT of LED luminaires with remote and close location of phosphor for 10 thousand hours of operation in different electric modes were obtained; the results of comparison between the initial and final radiation spectra of the luminaires are presented; using mathematical statistics methods, variation of luminaire CCT over the service period claimed by the manufacturer is forecast; the least favourable electric operation modes with the highest CCT variation observed are defined. The obtained results have confirmed availability of the problem of variation of CCT of LED luminaires during their operation. Possible way of its resolution is application of more qualitative and therefore expensive LEDs with close proximity of phosphor or LEDs with remote phosphor. The article may be interesting both for manufacturers and consumers of LED light sources and lighting devices using them.

Optical Properties and Zinc Nitride Thin Films Prepared Using Magnetron Reactive Sputtering

2014 ◽  
Vol 940 ◽  
pp. 11-15
Author(s):  
Jun Qin Feng ◽  
Jun Fang Chen
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Near Infrared ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Sem Images ◽  
Fluorescence Emission Spectra ◽  
Glass Substrates ◽  
Zinc Nitride ◽  
Direct Band

Zinc nitride films were deposited by ion sources-assisted magnetron sputtering with the use of Zn target (99.99% purity) on 7059 glass substrates. The films were characterized by XRD, SEM and EDS, the results of which show that the polycrystalline zinc nitride thin film can be grown on the glass substrates, the EDS spectrum confirmed the chemical composition of the films and the SEM images revealed that the zinc nitride thin films have a dense structure. Ultraviolet-visible-near infrared spectrophotometer was used to study the transmittance behaviors of zinc nitride thin films, which calculated the optical band gap by Davis Mott model. The results of the fluorescence emission spectra show the zinc nitride would be a direct band gap semiconductor material.

Stress and Phase Transformation Phenomena in Oxide Films: Real-Time Spectroscopic Measurements

1992 ◽  
Vol 271 ◽  
Author(s):  
Gregory J. Exarhos ◽  
Nancy J. Hess
Keyword(s):  
Phase Transformation ◽  
Applied Pressure ◽  
Oxide Films ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Film Deposition ◽  
Optical Methods ◽  
Fluorescence Emission Spectra ◽  
Line Intensities ◽  
Deposition Parameters

ABSTRACTIn situ optical methods are reviewed for characterization of phase transformation processes and evaluation of residual stress in solution-deposited metastable oxide films. Such low density films most often are deposited as disordered phases making them prone to crystallization and attendant densification when subjected to increased temperature and/or applied pressure. Inherent stress imparted during film deposition and its evolution during the transformation are evaluated from phonon frequency shifts seen in Raman spectra (TiO2) or from changes in the laser-induced fluorescence emission spectra for films containing rare earth (Sm+3:Y3Al5O12) or transition metal (Cr+3 :Al2O3) dopants. The data in combination with measured increases in line intensities intrinsic to the evolving phase are used to follow crystallization processes in thin films. In general, film deposition parameters are found to influence the crystallite ingrowth kinetics and the magnitude of stress and stress relaxation in the film during the transformation. The utility of these methods to probe crystallization phenomena in oxide films will be addressed.

scholarly journals Fluorescence emission spectra of silver and silver/cobalt nanoparticles

2012 ◽  
Vol 19 (3) ◽  
pp. 943-947 ◽  
Author(s):  
Z. Parang ◽  
A. Keshavarz ◽  
S. Farahi ◽  
S.M. Elahi ◽  
M. Ghoranneviss ◽  
...  
Keyword(s):  
Fluorescence Emission ◽  
Emission Spectra ◽  
Cobalt Nanoparticles ◽  
Fluorescence Emission Spectra

Modelling the effects of inter-observer variation on colour rendition

2017 ◽  
Vol 51 (1) ◽  
pp. 37-54 ◽  
Author(s):  
MJ Murdoch ◽  
MD Fairchild
Keyword(s):  
Colour Vision ◽  
Spectral Characteristics ◽  
Observer Variation ◽  
Light Sources ◽  
Standard Observer ◽  
Natural Range ◽  
Normal Colour ◽  
Range Of Variation

The colour rendition characteristics of light sources are quantified with measures based on CIE standard observers, which are reasonable representations of population averages. However, even among people with normal colour vision, the natural range of variation in colour sensitivity means any individual may see something different than the standard observer. Modelling results quantify the effects of these inter-observer differences on colour rendition measures defined by IES TM-30-15. In general, inter-observer differences tend to be smaller for light sources with high colour fidelity values, and they are affected by spectral characteristics of different lighting technologies. The magnitude of variation in colour rendition measures, up to 5–10 units in IES TM-30-15 ( Rf, Rg), measures is compared with other sources of variability and ambiguity.

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