Exploiting the optical sensing of fluorophore-tagged DNA nucleobases on hexagonal BN and Al-doped BN sheets: a computational study

It is necessary to have quantitative estimates of the intensity of lines (both absorption and emission) to obtain the physical parameters of the atmosphere of components.Some years ago at the Crimean observatory we began the spectroscopic investigation of close binary systems of the early spectral type with components WR, Of, O, B to try and obtain more quantitative information from the study of the spectra of the components.

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Polarimetric Observations of Red Variables: A Study of Gas and Particle Interactions

International Astronomical Union Colloquium ◽

10.1017/s0252921100073668 ◽

1979 ◽

Vol 46 ◽

pp. 386-408 ◽

Cited By ~ 2

Author(s):

G. V. Coyne ◽

I. S. McLean

Keyword(s):

Wavelength Dependence ◽

Stellar Atmosphere ◽

Molecular Absorption ◽

Absorption Bands ◽

Absorption And Emission ◽

Mira Variables ◽

Stellar Photosphere ◽

Regular Variable ◽

Red Supergiants ◽

Balmer Lines

AbstractIn recent years the wavelength, dependence of the polarization in a number of Mira variables, semi-regular variables and red supergiants has been measured with resolutions between 0.3 and 300 A over the range 3300 to 11000 A. Variations are seen across molecular absorption bands, especially TiO bands, and across atomic absorption and emission lines, especially the Balmer lines. In most cases one can ignore or it is possible to eliminate the effects due to interstellar polarization, so that one can study the polarization mechanisms operating in the stellar atmosphere and environment. The stars Omicron Ceti. (Mira), V CVn (semi-regular variable) and Mu Cephei (M2 la), in addition to other stars similar to them, will be discussed in some detail.Models to explain the observed polarization consider that the continuum flux is polarized either by electron, molecular and/or grain scattering or by temperature variations and/or geometrical asymmetries over the stellar photosphere. This polarized radiation is affected by atomic and molecular absorption and emission processes at various geometric depths in the stellar atmosphere and envelope. High resolution spectropolarimetry promises, therefore, to be a power-rul tool for studying stratification effects in these stars.

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Electron Microscopy of Nucleic Acids

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051529 ◽

1974 ◽

Vol 32 ◽

pp. 302-303

Author(s):

Norman Davidson

Keyword(s):

Electron Microscopy ◽

Nucleic Acids ◽

Basic Protein ◽

Molecular Biologist ◽

Topological Properties ◽

Protein Film ◽

Polynucleotide Chain

The basic protein film technique for mounting nucleic acids for electron microscopy has proven to be a general and powerful tool for the working molecular biologist in characterizing different nucleic acids. It i s possible to measure molecular lengths of duplex and single-stranded DNAs and RNAs. In particular, it is thus possible to as certain whether or not the nucleic acids extracted from a particular source are or are not homogeneous in length. The topological properties of the polynucleotide chain (linear or circular, relaxed or supercoiled circles, interlocked circles, etc. ) can also be as certained.

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mRNA localization by Electron microscopic in situ hybridization

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086453 ◽

1991 ◽

Vol 49 ◽

pp. 430-431

Author(s):

J. A. Pollock ◽

M. Martone ◽

T. Deerinck ◽

M. H. Ellisman

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

Nucleic Acids ◽

Recombinant Dna ◽

Light And Electron Microscopy ◽

Electron Microscopic ◽

High Voltage Electron Microscopy ◽

Functional Sites ◽

Voltage Electron

Localization of specific proteins in cells by both light and electron microscopy has been facilitate by the availability of antibodies that recognize unique features of these proteins. High resolution localization studies conducted over the last 25 years have allowed biologists to study the synthesis, translocation and ultimate functional sites for many important classes of proteins. Recently, recombinant DNA techniques in molecular biology have allowed the production of specific probes for localization of nucleic acids by “in situ” hybridization. The availability of these probes potentially opens a new set of questions to experimental investigation regarding the subcellular distribution of specific DNA's and RNA's. Nucleic acids have a much lower “copy number” per cell than a typical protein, ranging from one copy to perhaps several thousand. Therefore, sensitive, high resolution techniques are required. There are several reasons why Intermediate Voltage Electron Microscopy (IVEM) and High Voltage Electron Microscopy (HVEM) are most useful for localization of nucleic acids in situ.

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Nucleic Acid Molecules Prepared by Monolayer Techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100094140 ◽

1972 ◽

Vol 30 ◽

pp. 178-179

Author(s):

Dimitrij Lang

Keyword(s):

Electron Microscopy ◽

Standard Deviation ◽

Nucleic Acid ◽

Cytochrome C ◽

Nucleic Acids ◽

Contour Length ◽

Sample Standard Deviation ◽

Molecular Weights ◽

Length Measurements ◽

Protein Monolayer

The success of the protein monolayer technique for electron microscopy of individual DNA molecules is based on the prevention of aggregation and orientation of the molecules during drying on specimen grids. DNA adsorbs first to a surface-denatured, insoluble cytochrome c monolayer which is then transferred to grids, without major distortion, by touching. Fig. 1 shows three basic procedures which, modified or not, permit the study of various important properties of nucleic acids, either in concert with other methods or exclusively:1) Molecular weights relative to DNA standards as well as number distributions of molecular weights can be obtained from contour length measurements with a sample standard deviation between 1 and 4%.

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Snapshot blotting: The transfer of nucleic acids and nucleoprotein complexes from electrophoresis gels to EM grids

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124215 ◽

1992 ◽

Vol 50 (1) ◽

pp. 762-763

Author(s):

Stephen D. Jett

Keyword(s):

Nucleic Acid ◽

Nucleic Acids ◽

Nucleic Acid Binding ◽

Mobility Shift ◽

Carbon Coated ◽

Nucleoprotein Complexes ◽

Mobility Shift Assay ◽

Protein Nucleic Acid ◽

Gel Mobility Shift ◽

Nucleic Acid Interactions

The electrophoresis gel mobility shift assay is a popular method for the study of protein-nucleic acid interactions. The binding of proteins to DNA is characterized by a reduction in the electrophoretic mobility of the nucleic acid. Binding affinity, stoichiometry, and kinetics can be obtained from such assays; however, it is often desirable to image the various species in the gel bands using TEM. Present methods for isolation of nucleoproteins from gel bands are inefficient and often destroy the native structure of the complexes. We have developed a technique, called “snapshot blotting,” by which nucleic acids and nucleoprotein complexes in electrophoresis gels can be electrophoretically transferred directly onto carbon-coated grids for TEM imaging.

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Ultrastructural analysis of the spatial distribution of MRNA

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123167 ◽

1992 ◽

Vol 50 (1) ◽

pp. 552-553

Author(s):

Gary Bassell ◽

Robert H. Singer

Keyword(s):

Electron Microscopy ◽

Spatial Distribution ◽

In Situ Hybridization ◽

High Resolution ◽

Nucleic Acids ◽

Colloidal Gold ◽

Dna Probe ◽

Nucleotide Analogs ◽

Gold Particles

We have been investigating the spatial distribution of nucleic acids intracellularly using in situ hybridization. The use of non-isotopic nucleotide analogs incorporated into the DNA probe allows the detection of the probe at its site of hybridization within the cell. This approach therefore is compatible with the high resolution available by electron microscopy. Biotinated or digoxigenated probe can be detected by antibodies conjugated to colloidal gold. Because mRNA serves as a template for the probe fragments, the colloidal gold particles are detected as arrays which allow it to be unequivocally distinguished from background.

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