Principles and applications of red blood cell flow cytometry

Objective: In this review we address principles and important applications of flow cytometry in immunohematology. Sources and Criteria: Some studies o f the theoretical background and recent publications of current application s were selected. Results: The direct, indirect and two-color fluorescence a s well as the 'one-antigen-one-antibody' model are addressed. Possible stan dardizations and quality controls are discussed. Flow cytometric analyses w ith erythrocytes bear special problems such as agglutination, which is of l esser importance with other cells types. Possible applications include the quantitation of antigen density, antibody concentration, red blood cell bou nd immunoglobulin, and red blood cell subpopulations. Conclusion: Red blood cell flow cytometry is very sensitive, has a high pot ential for automatization, and hence may gain importance especially for man y routine tasks in the future.