New procedure for assay of lactobacilli using the luciferin-luciferase system.

Assay of rat plasma pyruvate kinase activity with luciferin-luciferase.

An assay method for pyruvate kinase in rat plasma is described. Plasma samples were incubated with ADP and phosphoenolpyruvate in Tris buffer solution. The ATP produced by pyruvate kinase was measured by photocounting after the addition of a commercially available luciferin-luciferase preparation. Interference by ATP or adenylate kinase originally present in the sample was removed by a high deg...

the use of appropriate madm model for ranking the vendors of mci equipments using fuzzy approach

abstract nowadays, the science of decision making has been paid to more attention due to the complexity of the problems of suppliers selection. as known, one of the efficient tools in economic and human resources development is the extension of communication networks in developing countries. so, the proper selection of suppliers of tc equipments is of concern very much. in this study, a ...

LightSwitchTM Luciferase Assay System

Membrane-permeable luciferin esters for assay of firefly luciferase in live intact cells.

Five esters of luciferin were synthesized and compared with native luciferin as substrates for firefly luciferase expressed in live intact mammalian cells. The esters themselves were not substrates for purified luciferase, but four were substrates for a purified esterase and all appeared to be hydrolysed to luciferin within mammalian cells. At a substrate concentration of 0.01 mM, the peak lumi...

Regulatory effects of ATP and luciferin on firefly luciferase activity.

ATP and luciferin are not only substrates of firefly luciferase, but can, in addition, modulate its activity. High concentrations of luciferin induce a conformational change of the enzyme that temporarily reduces the catalytic rate. Re-activation takes approx. 20 min and is independent of variation in the concentration of enzyme or ATP, but lengthens with increasing luciferin concentration. Hig...