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Proceedings Paper

Photoinduced autofluorescence modification of cells in an optical trap
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Paper Abstract

Photoinduced modifications of NAD(P)H attributed autofluorescence of CHO cells in a single- beam gradient force optical trap (optical tweezers) were studied. Fluorescence spectra of single cells in the optical trap were measured using a modified microscope with an IR microbeam at 1064 and 760 nm for trapping, UVA radiation at 365 nm for fluorescence excitation, and an optical multichannel analyzer for spectral recording. No strong effect of the 1064 nm trapping beam on fluorescence intensity and spectral characteristics was found, even for power densities up to 70 MW/cm2. In contrast, 760 nm microirradiation resulted in a significant fluorescence increase, probably indicating cell damage due to absorption by heme- containing molecules. UVA exposure (1 W/cm2) of the trapped cells generated within seconds an initial fluorescence decrease, followed by a significant increase up to 5X of the value prior to irradiation. The UVA-induced modifications reflect NAD(P)H auto-oxidation and irreversible cell damage due to oxidative stress.

Paper Details

Date Published: 1 February 1995
PDF: 11 pages
Proc. SPIE 2329, Optical and Imaging Techniques in Biomedicine, (1 February 1995); doi: 10.1117/12.200885
Show Author Affiliations
Karsten Koenig, Friedrich-Schiller-Univ. Jena (Germany)
Yagang Liu, Beckman Instruments, Inc. (United States)
Gregory J. Sonek, Univ. of California/Irvine (United States)
Michael W. Berns, Beckman Laser Institute and Medical Clinic (United States)
Bruce J. Tromberg, Beckman Laser Institute and Medical Clinic (United States)


Published in SPIE Proceedings Vol. 2329:
Optical and Imaging Techniques in Biomedicine

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