Simultaneous characterization of in vitro growing cells by fluorescence in situ hybridization (FISH) and Ki-67 labeling.

Because cytogenetic analysis and fluorescence in situ hybridization (FISH) techniques fail to provide information about the immunological phenotype with respect to differentiation and malignancy of in vitro growing cells, we developed a system which combines immunophenotyping and FISH. Using immunological detection of the proliferation fraction in short term human cell cultures from different origins by Ki-67 labeling and genetic characterization by FISH, both signals were detectable simultaneously on the same monolayer. Because determination of the proliferation behavior of tumor cells by Ki-67 labeling has now become a widespread laboratory tool, this particular technique may be very useful in tumor cell characterization. This approach allows genetic changes to be assigned to a particular immunological phenotype of individual cells.