OPTICAL TRAPPING OF CHROMOSOMES IN LIVING CELLS
Hong Liang
Institution:
Grant 5P41RR001192-170010 from National Center For Research Resources
Abstract: Our experimental results demonstrated that when optical trapping was applied to late-moving metaphase chromosomes, the trapped chromosomes initiated movement to the metaphase with the velocities two to eight times the normal rate depending on the chromosome size, geometry, and trapping site. At the initiation of anaphase, a pair of chromatids could be held by the optical trap and kept motionless throughout anaphase while the other pairs of chromatids separated and move to opposite spindle poles. A pulsed-laser microbeam (optical scissors) and laser-based trap (optical tweezers) have been successively combined to dissect and manipulate chromosome in PTK2 and newt lung epithelial cells. Our experiments demonstrate that the laser-based optical force trap is a potential new technique to study noninvasively the mitotic spindle , of living spindle, of living cells, and cell genetics.
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SUBCELLULAR PHOTOTOXICITY OF PHOTODYNAMIC THERAPY (PDT)
Hong Liang
Institution:
Grant 5P41RR001192-170009 from National Center For Research Resources
Abstract: Using bovine pulmonary artery endothelium cells (APAE), we determined some of the effects of PDT on subcellular areas of the APAE cells. Three hour treatment of 50 mg/ml ALA permitted optimal detection of fluorescence within the cell. Bright fluorescence was confined primarily to the mitochondria. There were no adverse effects in controls (with no ALA) while receiving five minutes of exposure, however, some of the cells with ALA appeared sick or lysed within 24 hours of exposure. Both cells with and without ALA were more sensitive to irradiation of the nuclei than irradiation of the cytoplasm. Almost all cells with ALA that had irradiation of the nuclei lysed with 24 hours of exposure.
LASER MEDIATED GENE TRANSFER IN HIGHER PLANTS
Hong Liang
Institution:
Grant 5P41RR001192-170005 from National Center For Research Resources
Abstract: An effective system for introducing exogenous DNA into cells of embryonic calli of Oryza sativa L. cv. Japonica has been established. Plant cells were pretreated in hypertonic buffer to draw some of the water from the cells and were then put into medium of less negative osmotic potential containing exogenous DNA and treated immediately with a laser microbeam (355nm) to puncture holes in the cell wall and membrane. Bright yellow-green fluorescence could be detected inside of cells which had been bathed in a solution containing the fluorescent molecule calcein. B-glucuronidase (GUS) genes were successfully introduced into rice cells as indicated by gene expression both in post-treated cells and in plantlets derived from kanamycin resistant calli that had been treated by this method.
SUBCELLULAR PHOTOTOXICITY OF PHOTODYNAMIC THERAPY (PDT)
Hong Liang
University Of California Irvine Irvine, Ca 926977600
Grant 5P41RR001192-180003 from National Center For Research Resources
Keywords: animal tissue, biological product, biomedical resource, drug screening /evaluation, health care, laser, microscopy, behavioral /social science research tag
OPTICAL TRAPPING OF CHROMOSOMES IN LIVING CELLS
Hong Liang
University Of California Irvine Irvine, Ca 926977600
Grant 5P41RR001192-180004 from National Center For Research Resources
Keywords: animal tissue, biomedical resource, biotechnology, laser, model design /development, technology /technique development
Grants awarded to Hong Liang
GENOME-WIDE ASSOCIATION STUDY OF PERIODONTITIS
Hong Liang
Tulane University Of Louisianacity: New Orleans country: United States (us)
Grant 7RC2DE020756-02 from National Institute Of Dental & Craniofacial Research
Project start date: 2009-09-25
Project end date: 2012-01-31
Budget start date: 1-JAN-2012
Budget end date: 31-JAN-2012
7RC2DE020756-02 (2009): $17308