RESUMEN
Abstract Use of Immunohistochemical Study in Pathology Unaporn Trongsakul BSc (Biology) Sujitra Tanvanich MSc (Pathobiology) Siriwan Tangjitgamol MD Department of Anatomical Pathology BMA Medical College and Vajira Hospital Immunohistochemistry is the application of immunologic technique used to determine types of antigen in cells or tissue structure. The staining is based on the principle of antigen-antibody binding compound. This compound could be detected by a catalytic chemical reaction of chromogen, producing specific color at specific cellular location. Used of immunohistochemical stain are: to detect the cancer cell origins, to classify the tumors, to demonstrate micrometastatic cancer cells, as a prognostic indicator and to identify microorganisms. Although the physicians who submit a tissue for histologic diagnosis do not require extensive knowledge on immunohistochemistry, basic information of the technique would help them understand the complicated pathological work. Furthermore, the knowledge or familiarity on this special technique would certainly assist them to collaborate with pathologists in making use out of these various immunohistochemistry stainings to facilitate the diagnosis and optimal care for the patients. Vajira Med J 2008 ; 52 : 285-291