Life-saving bone marrow and related stem cell transplants require accurate CD34+ cell enumeration to determine donor cells’ viability. USP offers resources and expertise to overcome enumeration variability issues that create inconsistent results.
USP <127> Flow Cytometric Enumeration of CD34+ Cells – Appearing in USP 40 (Official May 1, 2017)
Written by USP’s volunteer CD34+ Cells Expert Panel—comprised of scientific experts from industry, government, and academia—General Chapter <127> standardizes a flow cytometric enumeration method to achieve reliable, consistent CD34+ cell counts.
The chapter provides instructions and example figures for demonstrating sequential Boolean gating based on the ISHAGE protocol.
USP CD34+ Cell Enumeration System Suitability Reference Standard
- Made from mobilized peripheral blood collected by apheresis of a G-CSF-mobilized donor containing a known amount of CD34+ cells.
- Components are fixed and lyophilized to provide a stable reference standard with CD45 and CD34 staining, comparable to fresh G-CSF mobilized peripheral blood cells.
- Dependable calibrator—with well-defined range assigned by a multi-laboratory collaborative study—for assessing reagents and ensuring correct gating for data acquisition and analysis.
- Easily reconstitutes in water and is ready to use. No lysis steps required.