Biological, Medical, and Clinical Analysis

Fourier Transform Infrared (FTIR) imaging is a well-established analytical method for obtaining spectral and spatial information simultaneously in the micron-size domain. The technique has been applied across many different application areas, from polymer science to biomedical imaging. Over recent years, interest has increased in pushing the diffraction limited spatial resolution performance of FTIR imaging systems, primarily using synchrotron based systems.

Mammals require dietary-based polyunsaturated fatty acids (PUFA) such as docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (AA) for many biological processes, including normal functioning of the retina and brain. Fourier transform infrared (FTIR) imaging with high spatial resolution is a suitable tool to investigate the PUFA distribution in tissue sections from animal models of disease, providing comprehensive information of the biochemical components on the subcellular scale.

Fourier transform infrared (FTIR) microscopic imaging uses a combination of an FTIR spectrometer with a microscope and Focal Plane Array (FPA) detector. The method has been recognized as a powerful and versatile imaging tool in many disciplines, ranging from biomedical research through to materials science, art conservation and forensics.

The Coblentz Society and the Federation of Analytical Chemistry and Spectroscopy Societies (FACSS) recently named Professor Duncan Graham of the University of Strathclyde (Glasgow, Scotland) as the recipient of the Coblentz Society?s 2012 Craver Award.

The authors discuss the combined use of Raman and FT-IR spectroscopy in fields such as forensic science, biomedical science, catalysis, and polymers.

New research being conducted at the University of Arkansas is demonstrating that Raman spectroscopy can be used to detect and monitor circulating carbon nanotubes in vivo and in real time.

Using a new mass spectrometry technique and stem cells that can be made to produce either neurons or glial cells, a team of researchers at the Salk Institute for Biological Studies (La Jolla, California) identified a molecular signaling pathway that is required for the production of glial cells, yielding insight into the neurobiology of Down?s syndrome and several nervous system disorders characterized by too many glial cells.

The author examines NIR spectrometers and the technologies developed during the telecommunications boom of the late 1990s, focusing on miniaturized optical techniques generally called MOEMS.

The authors present the results of a study in which FT-IR-ATR and FT-Raman spectrosopies were used to probe the effects of pasteurization and spray drying on the secondary structure of soy protein isolate.

January 2007. This review article summarizes biological applications that utilize surface plasmon resonance, localized surface plasmon resonance, and surface-enhanced Raman spectroscopy.

Here the authors describe a new method for the identification of key volatile organic compound markers using mass spectrometry combined with gas chromatography.

In this article, the role of a triple-quadrupole mass spectrometer in performing in vitro studies of compound metabolic stability and identification of Phase I and II metabolites is demonstrated.

IR imaging provides a new tool for disease detection, revealing compositional and structural information in tissue previously not available with contrast staining.

The concentration dependent influence of Na+ and K+ions on mass spectra of peptides is shown with human gastrin as a model peptide. With electrospray ionization the doubly charged protonated molecule ion [M+2H]2+ is normally the preferred ionization product. However, trace amounts of alkali metal ions already form clusters (adducts) with the peptide molecule, such as [M+H+Na]2+, which become dominating at higher concentrations. With Na+/K+ concentrations below 0.1 mg/kg (ppm) only a few clusters appear, which allow the correct doubly charged molecule ion to be assigned for a subsequent MS–MS experiment. With concentrations of 10 ppm and higher the alkali clusters become the most abundant peaks in the spectrum, and the absolute sensitivity is decreased by a factor of 5–10. Experiments were performed with water and water–methanol mixtures with a known Na+/K+ +content.

Many important biological signals are triggered by the binding of a peptide hormone to its cognate receptor at the cell surface. Using stopped-flow fluorescence spectroscopy, the authors have been able to observe, in real time, ligand binding to epidermal growth factor receptors expressed at the surface of intact cells. This method allows for the measurement of kinetic association and dissociation rates with high data density in a native cellular environment, providing insights into the signal-initiation process in this system that have not been revealed through the determination of ligand-binding constants obtained by more traditional methods.

The element selenium plays three distinct roles in biological processes, functioning in turn as a toxicant, a chemopreventive agent, and a heavy metal antagonist. This article discusses current research associated with each role, and how ICP-MS can be employed to better understand and utilize selenium's properties.