IDENTIFICATION OF EARLY APOPTOSIS IN FEULGEN-STAINED CULTURED-CELLS IN-SITU BY COMPUTERIZED IMAGE-ANALYSIS

A method is presented in which Feulgen-stained apoptotic cells are ide ntified among cultured cells in situ using computerized image analysis of their nuclei. Images of ether control (untreated) human lymphoblas toid cell nuclei of of similar cells treated with 3mM methyl methanesu lfonate for 1 h, which induces apoptosis in 100% of the cells, were co nverted to a standard size (80 x 80 pixels) and Fourier transforms and boundary images based on 21 proportional mean gray-level thresholds o btained. The perimeter and the mean fractal dimension of the latter an d 39 selected coefficients of the former were then obtained from which data were chosen heuristically and subjected, to multivariate linear discrimination analysis. Eighty-two percent of a teaching set of 50 nu clei and 69% of a test set of 29 nuclei were correctly identified as a poptotic versus nonapoptotic by the computer, compared with 57% identi fied correctly by a panel of 7 pathologists. This study shows the feas ibility of using this type of analysis to directly identify apoptotic cells in culture, and probably also in tissues, by direct observation using computerized imaging technology. (C) 1998 Wiley-Liss,Inc.