Epifluorescence video microscopy is a valuable technique in the evaluation of the hemocompatilibity of biomaterials and has been used by several groups toward this end. The technique permits the observation of platelet and leukocyte interaction with materials which re in contact with whole human blood, either anticoagulated or native, under flow conditions of physiological relevance. The platelets, and other nonerythrocyte cells of the blood if desired, are labeled with a fluorophore. The potential for an experimental artifact due to photoactivation by the excitation light has recently been pointed out. Fluorescent dyes absorb at relatively short wavelengths, where the potential to interact destructively with proteins and cells is high. In this paper, we wish to describe conditions for use of this technique, as they have been practiced in this laboratory for several years, which avoid this potential for photoactivation. Furthermore, we wish to speculate and provide some evidence regarding the possible mechanism of the photoactivation event.
ASJC Scopus subject areas
- Biomedical Engineering