DRAQ5-based, no-lyse, no-wash bone marrow aspirate evaluation by flow cytometry

Area of Science:

• Hematology
• Immunophenotyping
• Cellular Analysis

Background:

• Flow cytometry (FC) is crucial for diagnosing hematolymphoid neoplasia.
• Conventional FC requires erythrocyte lysis, risking loss of critical cell populations like nucleated erythroid cells.

Purpose of the Study:

• To develop and validate a novel FC method for analyzing bone marrow aspirates (BMAs) without erythrocyte lysis.
• To minimize cell loss and improve the accuracy of differential counts in BMAs.

Main Methods:

• A new DRAQ5 protocol was developed, utilizing nuclear DRAQ5 fluorescence as a gating parameter.
• Bone marrow aspirates (BMAs) were analyzed using the DRAQ5 protocol with CD71 and CD45 antibodies.
• Results were compared to traditional morphologic study and erythrocyte lysis FC methods.

Main Results:

• The DRAQ5 protocol successfully preserved nucleated erythroid cells, unlike erythrocyte lysis methods.
• This preservation allowed for more accurate calculation of myeloid to erythroid ratios.
• The protocol provided blast and abnormal cell counts that better reflected morphologic differentials.

Conclusions:

• The DRAQ5 protocol offers a superior method for FC analysis of BMAs, enhancing diagnostic accuracy.
• This technique minimizes cell loss and improves the enumeration of critical cell populations, particularly nucleated erythroid cells.
• The method provides a more reliable assessment of marrow differentials compared to conventional erythrocyte lysis FC.