Bichromophoric Compounds with Orthogonally and Parallelly Arranged Chromophores Separated by Rigid Spacers.

Electronic energy transfer (EET) between chromophores is of fundamental importance for many biological processes and optoelectronic devices. However, common models fall short in fully describing the process, especially in bichromophoric model systems with a donor and acceptor connected by a rigid linker providing perpendicular geometries. Herein, we report a novel strategy for preparing bichromophores containing adamantane or 2-(2-adamantylidene)adamantane as rigid spacers, providing a fixed distance between chromophores, and their parallel or perpendicular arrangement without chromophore rotation.

Fluorescent Rhodamines and Fluorogenic Carbopyronines for Super-Resolution STED Microscopy in Living Cells.

A range of bright and photostable rhodamines and carbopyronines with absorption maxima in the range of λ=500-630 nm were prepared, and enabled the specific labeling of cytoskeletal filaments using HaloTag technology followed by staining with 1 μm solutions of the dye-ligand conjugates. The synthesis, photophysical parameters, fluorogenic behavior, and structure-property relationships of the new dyes are discussed. Light microscopy with stimulated emission depletion (STED) provided one- and two-color images of living cells with an optical resolution of 40-60 nm.

Polar red-emitting rhodamine dyes with reactive groups: synthesis, photophysical properties, and two-color STED nanoscopy applications.

The synthesis, reactivity, and photophysical properties of new rhodamines with intense red fluorescence, two polar residues (hydroxyls, primary phosphates, or sulfonic acid groups), and improved hydrolytic stability of the amino-reactive sites (NHS esters or mixed N-succinimidyl carbonates) are reported. All fluorophores contain an N-alkyl-1,2-dihydro-2,2,4-trimethylquinoline fragment, and most of them bear a fully substituted tetrafluoro phenyl ring with a secondary carboxamide group. The absorption and emission maxima in water are in the range of 635-639 and 655-659 nm, respectively.

Comparison of in-house allergen extracts of Phleum pratense (timothy grass) pollen with the international standard and investigation of IgE specificities of a grass-pollen serum pool from West Germany and of the one recommended by the World Health Organization.

We compared our in-house reference extract (RE) and a production extract (PE) with the international reference preparation (IRP) of International Union of Immunological Societies of timothy-grass pollen, using various biochemical and immunochemical methods. Furthermore, we compared the IgE composition of our in-house grass-pollen serum pool (West Germany) with the serum pool recommended by the World Health Organization, using the RE for crossed radioimmunoelectrophoresis (CRIE). Our extracts (RE and PE) were nearly comparable with the IRP.

Investigation of the allergenic activity of isolated fractions of a standardized partly purified whole mite body (Dermatophagoides pteronyssinus) extract.

Twelve fractions of a molecular weight range of 1.35-670.00 kilodaltons (kD) were isolated from a biologically standardized partly purified whole mite body extract (Dermatophagoides pteronyssinus) by preparative size exclusion high-performance liquid chromatography.