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A S Waggoner

Publications and source records attributed to A S Waggoner.

49 records · Page 3Linked to original sources
PubMed1970

Fluorescent probes of biological membranes.

FLUORESCENT AND PHOSPHORESCENT PROBES THAT HAVE READILY INTERPRETABLE EMISSION PROPERTIES CAN BE SPECIFICALLY INSERTED INTO BIOLOGICAL MACROMOLECULES TO REVEAL FACETS OF THEIR STRUCTURE AND DYNAMICS: (1) Proximity. Singlet-singlet and triplet-singlet energy transfer can serve as spectroscopic rulers in the 10-65 A range, whereas triplet-triplet transfer can be used to show that two groups are less than about 12 A apart. (2) Rotational mobility. Nanosecond fluorescence polarization measurements can reveal whether a macromolecular system has any modes of flexibility in times of nanoseconds. (3) Polarity. The presence of mobile dipoles in the environment of certain chromophores is reflected in their fluorescence quantum yield and emission spectrum. We have synthesized a number of new fluorescent probes for biological membranes. Anthroyl stearic acid (I), dansyl phosphatidyl ethanolamine (II), and octadecyl naphthylamine sulfonic acid (III) are readily incorporated into bilayer vesicles composed of phosphatidyl choline. The emission spectra of these probes in the vesicles indicate that the chromophore of I is located in the hydrocarbon region, that of II is located in the glycerol layer, and that of III is located at the aqueous interface of the bilayer. Thus, fluorescent chromophores can be selectively placed in different transverse regions of a model membrane system.

Anthracenes↗
PubMed1969

Orientation of lipid spin labels in lecithin multilayers.

Nitroxide-labeled stearic acid and cholestane have been incorporated into lecithin multilayers. The pronounced anisotropy of the preparations reflects a nonrandom structure of the lecithin film and demonstrates that these lipid probes can report structural information from lipid regions resembling those thought to occur in membranes. These two probes differ with respect to the orientation of the NO bond to the long axis, but both orient with their long axes perpendicular to the phospholipid film. Simulated spectra, calculated on the basis of a Gaussian distribution of orientations, are in agreement with the experimental results.

Electron Spin Resonance Spectroscopy↗
PubMedDate not supplied

Multiple spectral parameter imaging in quantitative fluorescence microscopy. I: Quantitation of bead standards.

Digitized images from fluorescence microscopy may suffer from nonlinearity of camera response to illumination intensity, from uneven spatial response of the camera, and from uneven illumination of the microscopical field. Structureless fluorescence standard slides are used to characterize the camera response. This information permits the images to be corrected for all the above errors, in one operation. The computer algorithms are described, and also those for thresholding and finding objects. The method is illustrated by tests using fluorescent beads.

Algorithms↗
PubMedDate not supplied

Cyanine dye labeling reagents: sulfoindocyanine succinimidyl esters.

A series of new fluorescent labeling reagents based on sulfoindocyanine dyes has been developed. We describe the synthesis and properties of these reagents. They contain succinimidyl ester reactive groups and can be readily conjugated to antibodies, avidin, DNA, lipids, polymers, and other amino-group-containing materials. The labeling reagents are water soluble, pH insensitive, and show much reduced dye aggregation under labeling conditions. One of the reagents, Cy3, can be excited with the 488-, 514- and 532-nm laser lines and is optimally excited with the 546-nm mercury arc line. Another, Cy5, can be excited with the 633-nm HeNe and 647-nm Kr laser lines available with many flow cytometers and confocal laser-scanning microscopes. New laser diodes emitting near 650 nm should also be excellent excitation sources for Cy5.

Antibodies↗
PubMedDate not supplied

Cyanine-labeling reagents: sulfobenzindocyanine succinimidyl esters.

A synthetic method for shifting the absorption and emission wavelengths of cyanine dye labels by 15-30 nm to the red has been developed. This step significantly increases the potential for preparing fluorescent probes for multiparameter analysis in cytometry and diagnostics. The new sulfobenzindocyanine dyes contain succinimidyl esters as reactive groups and can be readily conjugated to antibodies, avidin, modified DNA, and other amino group-containing materials. The labeling reagents are water soluble, and their fluorescence is not sensitive to pH. One of the reagents, Cy3.205, can be optimally excited with the 568 nm Kr laser line and is useful for confocal microscopy and flow cytometry. Another dye, Cy5.205, can be excited with the 633 He-Ne or 647 nm Kr laser lines available with many flow cytometers and laser-scanning microscopes. New laser diodes emitting near 660-690 nm should also be excellent excitation sources for Cy5.205.

Animals↗