PARAMETRES PHYSIQUES CARACTERISANT LE DOMMAGE THERMIQUE SELECTIF DE MITOCHONDRIES EN MICRO‐IRRADIATION PAR LASER

Abstract
Abstract— Laser micro‐irradiation was used to study the uptake of low levels of strain (Janus Green B) by the mitochondria of tissue culture cells and the selective lesions induced by the irradiation. A comparison of the thermal effects produced in the cells and in a stained model system (albumin), permitted the calculation of the degree of concentration of stain in the mitochondria from the staining media (approximately 500 fold). Evaluation of the various parameters of Laser irradiation, particularly thermal events, resulted in optimal irradiation times for measurement of local stain concentration, as well as for the selective destruction of the stained mitochondria. For the studies of the latter phenomenon a lower limit for irradiation duration is set by optical saturation and dielectric breakdown.