1 January 2000 Cell viability in optical tweezers: high power red laser diode versus Nd:YAG laser
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J. of Biomedical Optics, 5(1), (2000). doi:10.1117/1.429966
Abstract
Viability of cultivated Chinese hamster ovary cells in optical tweezers was measured after exposure to various light doses of red high power laser diodes (?=670–680 nm) and a Nd:yttrium– aluminum–garnet laser (?=1064 nm). When using a radiant exposure of 2.4 GJ/cm2, a reduction of colony formation up to a factor 2 (670– 680 nm) or 1.6 (1064 nm) as well as a delay of cell growth were detected in comparison with nonirradiated controls. In contrast, no cell damage was found at an exposure of 340 MJ/cm2 for both wavelengths, and virtually no lethal damage at 1 GJ/cm2 applied at 1064 nm. Cell viabilities were correlated with fluorescence excitation spectra and with literature data of wavelength dependent cloning efficiencies. Fluorescence excitation maxima of the coenzymes NAD(P)H and flavins were detected at 365 and 450 nm, respectively. This is half of the wavelengths of the maxima of cell inactivation, suggesting that two-photon absorption by these coenzymes may contribute to cellular damage. Two-photon excitation of NAD(P)H and flavins may also affect cell viability after exposure to 670–680 nm, whereas onephoton excitation of water molecules seems to limit cell viability at 1064 nm.
Herbert Schneckenburger, Anita Hendinger, Reinhard Sailer, Michael H. Gschwend, Wolfgang S. L. Strauss, Manfred Bauer, Karin Schuetze, "Cell viability in optical tweezers: high power red laser diode versus Nd:YAG laser," Journal of Biomedical Optics 5(1), (1 January 2000). http://dx.doi.org/10.1117/1.429966
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KEYWORDS
Optical tweezers

Semiconductor lasers

Luminescence

Nd:YAG lasers

Absorption

Control systems

High power lasers

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