GFP fluorescence imaging with laser confocal scanning microscope

Abstract

ABSTRACT With gene marking technique, green fluorescent protein (GFP) and nodule bacteria gene has been linked together toform a single fusion gene expression vector. Then the vector is transferred into the nodule bacteria and the astragalus sinicusis invaded by the vector. With laser conlocal scanning microscope (LCSM), some important morphological information inplant nitrogen fixation research about the invading of nodule bacteria and the formation process of root nodule has beenobtained through the three-dimensional imaging of GFP reporting fluorescence. Keywords: laser confocal scanning microscope, three-dimensional imaging, GF1 astragalus sinicus, DNA reconstruction, GFP marking technique, nodule bacteria, root nodule, invading line, nitrogen fixation 1. INTRODUCTIONTo clarify the diverse biological activity process and its regularity in intact living cells in molecular level is the objective of the study of molecular biology. But before the appearance of GFP, almost all the study methods demand fixingor destroying the cell. Even the macromolecular fluorescence marking technique can only study some specific molecularprocesses under specific conditions in living cells. And its experiment operation is very complex and can only meet thedemand of short time observation.The appearance of the GFP marking system overcomes the above defects thoroughly'23. With DNA reconstructiontechnique, the GFP gene and the objective protein gene is linked together. Then a single fusion gene expression vector isformed. If the objective protein gene is expressed, the GFP gene can be expressed simultaneously. So we can trace theexpression and the time-space features of the objective protein gene through detecting the fluorescence of GFP GFP nowbecomes a very important method in genetics research. Also the generation of GFP fluorescence need not any auxiliaryelements or substrates. So with the GFP marking system, researchers can do direct observations and studies to the diverseprocesses carried out in living cells or living biological tissues and its molecular mechanisms under normal physiological