The specimen is a monolayer of A549 human lung carcinoma in tissue culture that was triple-stained using a mixture of TRITC, FITC, and DAPI. Photomicrographs were recorded utilizing a UPL 40x apochromatic objective coupled to a WIBA/WU dichroic filter combination. A 3.3x projection photo eyepiece was used to transfer light from the intermediate image plane to the photographic emulsion.