Improved bone marrow differential method with DRAQ5

In the May 2008 issue of the Am. J. Clin. Path. Robert W. Allan et al. (Gainesville, USA) describe an exciting new method which gives improved flow cytometric analysis of clinical bone marrow aspirates for the evaluation of hematolymphoid neoplasia.

Specifically, this no lyse, no wash method uses DRAQ5 to gate the nucleated cells and, importantly the authors state, "results in a more accurate representation of nucleated precursors and the M/E ratio than lysis FC [flow cytometry] and, thus, may be used as a means to objectively and rapidly analyze bone marrow samples."

It is apparent from the data that this non lysis method give more reliable M/E ratios due to the improved retention of intact nucleated erythroid precursors. These cells appear to suffer from lysis in the comparable procedure relying on RBC lysis reagents.

The spectral properties of DRAQ5 allow the use of FITC/PE antibody pairs and three colour analysis using only the 488nm laser excitation. Its ability to efficiently label the DNA of live cells allows its use as a nucleated cell gating parameter.

Allan RW, Ansari-Lari MA and Jordan S. DRAQ5-based, no lyse, no wash bone marrow aspirate evaluation by flow cytometry. Am J Clin Path 2008; 129: 706-713