Photosystem II (PSII) is a huge pigment-protein supercomplex responsible for the primary steps of photosynthesis in green plants. Its light-harvesting antenna exhibits efficient transfer of the absorbed excitation energy to the reaction center and also contains a well-regulated protection mechanism against over-excitation in strong light conditions. The latter is based on conformational changes...

Chemical compositions, volatile compounds and sensory property of Kapi produced from two shrimp species, Acetes vulgaris and Macrobrachium lanchesteri, were comparatively determined. Kapi produced from M. lanchesteri (KM) had the higher protein content but lower fat content, compared with that from A. vulgaris (KA) (p < 0.05). However, KA showed higher browning intensity (A420) and fluorescence...

This heterogeneous assay for tobramycin involves fluorescein-labeled tobramycin, which competes with native unlabeled tobramycin for anti-tobramycin binding sites. Bound and free labeled antigen are separated by precipitation with a second antibody. Fluorescence intensity of the resuspended precipitate is inversely proportional to native tobramycin concentration. Background interference was con...

Fluorescence of green fluorescent protein mutant, 2-5 GFP is observed during denaturation by guanidine. The fluorescence intensity decreases exponentially but the fluorescence lifetime does not change during denaturation. The fluorescence lifetime of the denatured protein is shorter than that of native form. As the protein structure is modified by guanidine, solvent water molecules penetrate in...

Article info: Received: 25 June 2014 Accepted: 13 November 2014 ABSTRACT Glutamine synthetase, an important enzyme of nitrogen metabolism, was purified under sporulating conditions (GSala). The effect of ligands on the tryptophan fluorescence of the purified enzyme GSala was investigated. With increasing concentrations of L-glutamine in GSala, a blue shift in emission maximum with an increase i...

Borreliacidal antibody has been shown to be important for the serodiagnosis of Lyme disease and determination of immune status. Our results show that borreliacidal antibody can be rapidly and accurately detected by flow cytometry. Acridine orange was added to normal and immune sera containing Borrelia burgdorferi organisms in the presence and absence of complement prior to data acquisition by f...

The intensity of chlorophyll a fluorescence during the early part of fluorescence induction at 0, initial fluorescence, and P, peak fluorescence, was higher during the day phase of the circadian cycle than during the night phase in continuous light (LL) conditions and was positively correlated with the rate of oxygen evolution. The circadian rhythm in fluorescence in LL persisted in the presenc...

The fluorescence intensity profiles of thin cross-sections of human lenses were determined as a function of age by scanning microspectrofluorimetry with blue light excitation close to that available in conventional slit-lamp examination (filter transmission maximum 410 nm). The fluorescence intensity of the entire nuclear region increased with age. The profile of the adult lens was manifested a...

The fluorescent Ca2+ sensitive dyes Fura Red (ratiometric) and Fluo-4 (non-ratiometric) are widely utilized for the optical assessment of Ca2+ fluctuations in vitro as well as in situ. The fluorescent behavior of these dyes is strongly depends on temperature, pH, ionic strength and pressure. It is crucial to understand the response of these dyes to pressure when applying calcium imaging technol...