Automated method for analysis of tryptophan and tyrosine metabolites using capillary electrophoresis with native fluorescence detection.

Capillary electrophoresis (CE) with laser-induced native fluorescence (LINF) detection offers the ability to characterize low levels of selected analyte classes, depending on the excitation and emission wavelengths used. Here a new automated CE-LINF system that provides deep ultraviolet (DUV) excitation (224 nm) and variable emission wavelength detection was evaluated for the analysis of small molecule tryptophan- and tyrosine-related metabolites. The optimized instrument design includes several features that increase throughput, lower instrument cost and maintenance, and decrease complexity when compared with earlier systems using DUV excitation.

Serotonin of mast cell origin contributes to hippocampal function.

In the central nervous system, serotonin, an important neurotransmitter and trophic factor, is synthesized by both mast cells and neurons. Mast cells, like other immune cells, are born in the bone marrow and migrate to many tissues. We show that they are resident in the mouse brain throughout development and adulthood.

Direct determination of effective interfacial optical constants by nonlinear optical null ellipsometry of chiral films.

Nonlinear optical null ellipsometry (NONE) measurements of chiral interfaces allowed direct experimental measurement of the linear interfacial optical constants in surface second harmonic generation (SHG) measurements. Since phase information is retained in NONE measurements, the real and imaginary components of the interfacial refractive index (n and k, respectively) were uniquely obtained from the measured chiral chi((2)) tensor elements of a fluorescein-labeled bovine serum albumin film. The sensitivity of the calculated chi((2)) tensor elements on the assumed values of the interfacial optical constants allowed measurements of n and k to four significant figures with no additional adjustable parameters and independent of molecular symmetry.