Cryopreservation modifies flow-cytometric analysis of hemopoietic cells

Area of Science:

• Hematology
• Cell Biology
• Biotechnology

Background:

• Cryopreservation of human bone marrow is a common medical practice.
• Limited understanding exists regarding cryopreservation's effects on hemopoietic cells.
• Flow cytometry is crucial for analyzing bone marrow cell populations.

Purpose of the Study:

• To investigate how bone marrow processing and cryopreservation affect flow cytometric analysis.
• To determine the impact of buffy coat concentration, DMSO exposure, and freeze-thaw rates on hemopoietic cells.
• To assess changes in cell subset proportions and surface antigen expression.

Main Methods:

• Human bone marrow samples were processed into buffy coats.
• Samples were exposed to dimethyl sulfoxide (DMSO).
• Controlled freezing and thawing procedures were applied.
• Flow cytometry was used to analyze cell populations and antigen expression (CD7, CD13, CD33, CD34, CD19).

Main Results:

• DMSO exposure and cryopreservation significantly altered hemopoietic cell subset proportions.
• Percentages of CD7, CD13, CD33, and CD34 expressing cells decreased after DMSO exposure and cryopreservation.
• CD33 antigen expression intensity decreased with DMSO exposure and further with cryopreservation.
• CD19 antigen expression intensity increased in cryopreserved samples compared to fresh samples.

Conclusions:

• Flow cytometric analysis of cryopreserved human bone marrow is not equivalent to fresh samples.
• DMSO exposure and cryopreservation procedures induce significant changes in hemopoietic cell markers.
• Careful consideration of these modifications is necessary for accurate interpretation of flow cytometry data from processed bone marrow.