Provided is a method for determining effectiveness of
medicine containing, as components, antibodies that are
active components of an
antibody preparation such as
trastuzumab, or antibodies for a target to a
target site of
active component, by determining the quantity of the
protein recognized by the antibodies with high accuracy, in a quantitative
tissue staining method for
biological tissue. The effectiveness of the
medicine containing antibodies as components is determined by using the
tissue staining method including the following steps: a step of labeling the antibodies in a
medicine that contains antibodies as components with a fluorescent substance, and bringing the fluorescently labeled antibodies into contact with a
tissue sample; a step of irradiating the tissue site contacted with the antibodies with excitation light to obtain a
fluorescence image; a step of obtaining an
intrinsic fluorescence image in the vicinity of the short-
wavelength side or long-
wavelength side of the acquisition area of
fluorescence wavelength emitted from the fluorescent substance, in the same field of vision and in the same focus as those of the
fluorescence image; a step of obtaining a collected fluorescence image by image-
processing to eliminate the fluorescent intensity of the
intrinsic fluorescence image from the fluorescent intensity of the fluorescence image; a step of counting the number of cells at the tissue site contacted with the antibodies; a step of measuring the average fluorescent intensity of one particle of fluorescent particles; and a step of calculating the number of fluorescent particles per
cell.