Serology for Automated Cytotoxicity Assays: Contrast Fluorescence Test

Abstract.We have developed a new serologic method for the study of lymphocytotoxic reactions, based on differential fluorescent staining. Living cells, labeled with fluorescein diacetate, show green fluorescence, while dead cells are stained by ethidium bromide and show red fluorescence. Since both living and dead cells can be quantitated, the test is more sensitive. Because the total number of cells present can be quantitated, the estimations can be made by automatic equipment without the danger of false negatives resulting from the absence of cells.