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Biomedical subjects

L J Kricka

Publications and source records attributed to L J Kricka.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Imaging of chemiluminescent reactions in mesoscale silicon-glass microstructures.

Chemiluminescent reactions in mesoscale analytical structures (chips) containing micrometre-sized interconnecting channels and chambers (pL-nL total volume) were imaged. The chips were fabricated by bonding Pyrex glass to etched pieces of silicon using a high-temperature diffusive bonding technique. In initial experiments light emission from an enhanced chemiluminescent horseradish peroxidase reaction and from a peroxyoxalate reaction contained in straight channels (300 microns wide x 20 mu deep; volume 70.2 nL) and open chambers (812 microns wide, 400 microns deep, 5.2 mm long) linked by channels (100 microns wide, 20 microns deep) to an exit and entry port were studied using a specially modified microplate holder and an Amerlite microplate luminometer. Light emission from more complex structures (two chambers interconnected by a branching channel 100 microns wide, 20 microns deep) filled with a solution containing alkaline phosphatase, Emerald, and CSPD was imaged using a Photometrics Star 1 CCD camera. Detailed investigation of the detection and spatial resolution of the signal was performed on a Berthold Luminograph LB 980 using both the enhanced chemiluminescent horseradish peroxidase reaction and a peroxyoxalate reaction. We successfully resolved light emission from silicon structures with dimensions 100 microns wide and 20 microns deep. These simple silicon structures served as models for more complex designs that will be used for simultaneous multi-analyte assays in which an imaging system resolves and quantitates light emission from different locations on a silicon-glass analytical device.

Glass↗
PubMedDate not supplied

4-Phenylylboronic acid: a new type of enhancer for the horseradish peroxidase catalysed chemiluminescent oxidation of luminol.

4-Phenylylboronic acid enhances the light emission from the horseradish peroxidase catalysed oxidation of luminol by hydrogen peroxide. Optimization studies showed that the greatest enhancement was obtained using micromolar concentrations of the new enhancer. The largest degree of enhancement was found with the basic isoenzyme of horseradish peroxidase (Type VIA), and lesser degrees of enhancement were obtained with Type VII and Type IX horseradish peroxidase. The enhancer was also effective in the peroxidase catalysed oxidation of isoluminol by peroxide.

Boronic Acids↗
PubMedDate not supplied

New enhancers for the chemiluminescent peroxidase catalysed chemiluminescent oxidation of pyrogallol and purpurogallin.

The effects of various boronate compounds, 4-biphenylboronic acid, 4-bromobenzene-boronic acid, trans-4-(3-propionic acid)phenylboronic acid and 4-iodophenylboronic acid, on the horseradish peroxidase (HRP) catalysed chemiluminescent oxidation of pyrogallol and purpurogallin by peroxide were investigated. trans-4-(3-Propionic acid)phenylboronic acid produced a 13.7-fold enhancement in the peak light emission from the chemiluminescent HRP catalysed pyrogallol reaction (detection limit for HRP < 1.25 fmol). At low enhancer concentration a single peak of light emission was observed and as the enhancer concentration increased the time to peak light emission became progressively longer. The chemiluminescence showed two peaks at higher concentrations (> 54.3 mumol/L) and the individual peak times depended upon the concentration of the enhancer. All of the boronates enhanced peak light emission in the chemiluminescent HRP catalysed purpurogallin reaction. 4-Biphenylboronic acid was the most effective and it enhanced peak light emission 314-fold. The practical detection limit for HRP (Type VIA) using this enhancer was 4.18 pmol (peak emission at 20 minutes). This compound also enhanced peak light emission 232-fold from a chemiluminescent HRP-purpurogallin reaction in which molecular oxygen replaced peroxide as the oxidant.

Antioxidants↗
PubMedDate not supplied

Influence of different luminols on the characteristics of the chemiluminescence reaction in human neutrophils.

In search for a luminol with very high output of light, 20 different luminol samples were tested for their ability to enhance the chemiluminescence reaction in phorbol myristate acetate activated human neutrophils. We found that the majority of luminols tested (17 samples) gave almost the same light output from neutrophils, and that the major part of the activity was from an intracellular origin. Owing to the fact that three isoluminol samples were unable to monitor respiratory burst activity taking place intracellularly, a very low level of chemiluminescence was obtained with these samples. Their light output was, however, greatly increased when horseradish peroxidase or myeloperoxidase was added, showing that the light-generating reaction with isoluminol as well as with luminol is peroxidase-dependent. The fact that isoluminol could also use myeloperoxidase as amplifying peroxidase, suggests that that the lack of measurable intracellular activity in the presence of isoluminol is somehow related to a limited or restricted diffusion of the molecule to intracellular sites. The isoluminol system constitutes a sensitive system for measuring release of oxygen metabolites from phagocytic cells.

Adult↗
PubMedDate not supplied

Bibliography. Luminescence literature. Obelia, Renilla, Aequorea and Gonyaulax.

The journal provides comprehensive literature searches on all aspects of luminescence which will be published in most issues. These lists have been produced regularly since 1986-some by year and some by specialized topic. This survey of papers on Obelia, Renilla, Aequorea and Gonyaulax is drawn from the 2000 literature and covers the biology of these organisms and the applications of genes and proteins from these organisms in analysis.

Animals↗
PubMedDate not supplied

Bibliography. Luminescence literature. Chemiluminescent and bioluminescent immunoassays.

The Journal provides comprehensive literature searches on all aspects of luminescence, which will be published in most issues. These lists have been produced regularly since 1986-some by year and some by specialized topic. This survey of papers on chemiluminescent and bioluminescent immunoassays is drawn from the 2000 literature and covers reagents, assay development and validation, and applications.

Animals↗