In the May 2008 issue of the American Journal of Clinical Pathology, Allan et al (Gainesville, US) describe a method that gives improved flow cytometric analysis of clinical bone marrow aspirates.
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 M/E ratio than lysis FC (flow cytometry) and thus, may be used as a means to objectively and rapidly analyse bone marrow samples.' It is apparent from the data that this no-lyse method gives 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.
