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TIME‐RESOLVED STUDIES OF SINGLET‐OXYGEN EMISSION FROM L1210 LEUKEMIA CELLS LABELED WITH 5‐( N‐HEXADECANOYL )AMINO EOSIN. A COMPARISON WITH A ONE‐DIMENSIONAL MODEL OF SINGLET‐OXYGEN DIFFUSION AND QUENCHING
Author(s) -
Baker Ayse,
Kanofsky Jeffrey R.
Publication year - 1993
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1993.tb02944.x
Subject(s) - singlet oxygen , chemistry , photochemistry , quenching (fluorescence) , oxygen , singlet state , histidine , excited state , fluorescence , organic chemistry , optics , atomic physics , physics , enzyme
— Time‐resolved measurements were made of near‐infrared emission from 5‐( N ‐hexadecanoyl)amino‐eosinlabeled L1210 leukemia cells following pulsed‐laser excitation. The cells were suspended in phosphate‐buffered saline made with deuterium oxide solvent. A significant fraction of the emission occuring10–80 μs after the laser pulse was due to singlet oxygen. This singlet‐oxygen emission is believed to result from singlet oxygen generated near the cell‐membrane surface, where 5‐( N ‐hexadecanoyl)amino eosin is known to concentrate, and then diffusing out into the buffer. The intensity and the kinetics of the experimentally observed singlet‐oxygen emission were in excellent agreement with the predictions of a theoretical one‐dimensional model of singlet‐oxygen diffusion and quenching. During the10–80 μs time period studied, most of the singlet oxygen was located in the buffer. Thus, the use of water‐soluble singlet‐oxygen quenchers, such as histidine, provide one means of separating the singlet‐oxygen emission quenchers, such as histidine, provide one means of separating the singlet‐oxygen emission from other sources of light during this time interval.