Patent ID: 8343733

Claim:
A method of staining or pre-staining a plurality of cells, the method comprising: (a) fixing the plurality of cells with a fixative to thereby obtain a plurality of fixed cells; (b) contacting the plurality of fixed cells with a staining agent consisting of an extract of a Ficus elastica plant, thereby staining or pre-staining the plurality of cells; and (c) contacting said plurality of fixed cells with at least one dye, wherein when: (i) said at least one dye is an acidic dye a staining intensity above a predetermined threshold is indicative of differentiated cells; (ii) said at least one dye is a basic dye a staining intensity above a predetermined threshold is indicative of undifferentiated cells; (iii) said at least one dye comprises said acidic dye and said basic dye a staining intensity above a predetermined threshold with said acidic dye is indicative of differentiated cells and a staining intensity above a predetermined threshold with said basic dye is indicative of undifferentiated cells.