Analytical morphology is a contemporary science dealing with the analy sis of shape, size, and color arrangement of cell and tissue component s by means of a variety of analytical methods. To a great extent, the advancement of analytical morphology is based on new advances in other disciplines, such as immunology, molecular biology, laser technology, microwave technology, and computer science. Using these new methods, particular cellular components that would otherwise remain invisible, such as peptides, proteins, or nucleotide sequences, are highlighted b y visible markers through chemical, physical, immunological, or molecu lar biological reactions. These methods include immunocytochemistry, i n situ hybridization, in situ polymerase chain reaction, antigen retri eval, and image analysis.