Pathology, more than any other discipline, relies on the new biology of medicine, which comprises (1) molecular biology, (2) cell biology, (3) genetics, (4) immunology, (5) reproductive biology, and (6) neurobiology.1 Major developments in pathology within the last year and a half include the provision, by molecular biology and immunology, of methods for determining cell structure and function. The tool of molecular biology is the DNA probe, a single strand of DNA complementary to the free single strand of fixed DNA fragments of the specimen (cells, tissue).
Under optimal conditions, the DNA probe will hybridize with any complementary free strand. The single-stranded DNA probe (probing for its complementary half) is to molecular biology/ pathology a highly specific detector comparable with the antigen-antibody phenomena of immunology. The DNA hybridization techniques have been useful in the diagnosis of malignant lymphoproliferative disorders according to lineage and level of differentiation. The first step