A method for observing the morphology of a biological tissue is disclosed. The method involves administering a combination of fluorescent dyes into the biological tissue. The combination of fluorescent dyes includes two or more fluorescent dyes selected from a group consisting of: patent blue V, isosulfan blue, toluidine blue, hypericin, indocyanine green, MVAC, and doxorubicin. The method further involves using a microscopic imaging system to form an image of the biological tissue. The microscopic imaging system forms the image based on a contrast resulting from the combination of fluorescent dyes. A concentration of the first fluorescent dye depends on an administration route. A fluorescence of the combination of fluorescence dyes reveals the morphology of the biological tissue at a cellular scale. The fluorescence is observed by means of one of: ex vivo microscopy and in vivo microscopy.
