The paper analyzes in detail various aspects of semiautomatic quantitative analysis of the results of immunohistochemical reaction using the Morphology 5.0 computer program to analyze microscopic images. Various procedures for assessing the extent of expression of nuclear and cytoplastic markers are compared and a rationale is provided to choose the value of the relative area of a microimage. The authors have developed a new method for calculating the optical density of as an indicator of the intensity of expression of the marker under study, which allows one to effectively separate the study staining from the baseline hematoxylin staining. immunohistochemistry, quantification of expression, computer-aided analysis of images.