Field-Stain Solution A is a key component in the microscopic imaging of cells and parasites. The contained dyes methylene blue and azure II bind selectively to nucleic acids and proteins in cell nuclei and produce a visible color pattern. This specific affinity enables the differentiation and identification of cell nuclei and intracellular parasites such as malaria pathogens. After treatment with Solution A, Field-Stain Solution B is used to stain the cytoplasm and other cellular structures to complete the overall picture. In combination, the two solutions provide a comprehensive, differentiated picture of the cells examined and enable the identification and classification of intracellular parasites.