CUBIC: a three-dimensional colored projection of Consort 30 generated trivariate flow cytometric data.

The CUBIC program displays three-dimensional colored dot plots of flow cytometric trivariate data collected by unmodified commercial instruments (FACScan flow cytometer, FACS 440 cell sorter). Assuming a bimodal distribution of the fluorescence intensity of the cells, the eight theoretical subpopulations involved in a three-color fluorescence histogram are clearly localized in the 3-D space by colored dots that are clustered near each corner of a cubic frame. Rotation, tilting, and zoom functions are available. Table look-up is not needed. CUBIC was illustrated by two experiments: 1) three-color immunofluorescence of antigens on human lymphocytes using monoclonal antibodies conjugated either to fluorescein (FITC), to R-phycoerythrin (PE), or to biotin revealed by a streptavidin coupled to a PE-Texas red tandem conjugate (TC); 2) two-color immunofluorescence of CD4 and CD8 antigens on thymocytes of healthy or preleukemic mice correlated to the DNA content quantified by 7-amino-actinomycin D (7-AAD). The three fluorescences were excited by a single argon-ion laser emitting at 488 nm.