Haemopoietic stem cells in the bone marrow can be identified by their expression of CD34. Normally, the number of such cells in bone marrow is low and is negligible in peripheral blood. However, if mobilisation of CD34 positive cells from the bone marrow is stimulated, stem cells can be harvested from the peripheral blood as well as the marrow. These cells can be used to repopulate a depleted bone marrow after, for example, high dose chemotherapy. 
AntiHLA-DR reacts with many cells in the lymphoid, myeloid, and monocytic lineages while CD34 only recognizes precursor cells from early stages in the lineages. These reagents are useful in the research of acute leukemias. The addition of CD45, in conjunction with side scatter, might be useful as a gating aid for blast identication.
Further this combination is useful in the immunological detection of blast cell subpopulations in acute myeloblastic leukemia at diagnosis implications for minimal residual disease studies1.
The study of HLA-DR association in childhood acute lymphoblastic leukemia is proposed in some studies2.
The immunophenotype of acute promyelocytic leukemia (APL)4 or the study of HLA-Dr in acute non-lymphocytic leukemia3 are other clinical applications for this product.