Today the analysis repertoire of most large, credited clinical laboratories includes a number of flow cytometric tests as a diagnostic routine.
The first cytometric tests to demonstrate clinical value in the decision-making process were T CD4+ cell counts in HIV+ patients and the analysis of lymphocyte subsets in the Bronchoalveolar Lavage.
The next stage was flow cytometric analysis of leukemia/lymphoma and of circulating hematopoietic cell precursors, which rapidly become commonplace all over the world.

It is interesting to note that a number of alternative, non cytometric tests were developed for the same purposes at the same time, but they were invariably abandoned because of their poor performance, high labour-intensiveness and cost.
Because it performed far better than any alternative tests in many instances, flow cytometry gradually gained credit and trust in the clinical laboratory.

Flow cytometry therefore became the best way, and sometimes the only way, to perform delicate clinical tests with the necessary precision, accuracy, specificity, sensitivity and speed.

Nowadays one can consider the role of a flow cytometric facility in a credited clinical laboratory to be the dedicated section for carrying out crucial tests, such as the phenotyping of hematological malignancies, cell subset analysis and stem cell transplantation, as well as filling the gaps left by the ordinary laboratory equipment in a number of niche applications, such as feto-maternal hemorrhage, sepsis activation, PNH analysis, in vitro basophil activation by tricky allergens, control of leukoreduced blood products, HLA single-antigen screening, HIT analysis, red cell sport doping and many others.

This means that the clinical flow cytometry laboratory has a unique opportunity to support a number of different medical specialties and that the dedicated scientists must be especially knowledgeable, well-trained and open-minded people.

The clinical cytometry laboratory now enjoys the full coverage of stringent and internationally credited External Quality Assessment Schemes, which protect the patient and the operator from error and data misinterpretation.

Clinical cytometry offers one of the few remaining opportunities to develop skills and expertise in a challenging diagnostic arena.