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CD34+ Enumeration of
AllCells Fresh Tissue Products

How many CD34+ cells are in your AllCells tissue products?

CD34+ hematopoietic stem cells (HSC) are precious human cells for developing cell and gene therapies. However, only a very limited amount of HSCs can be collected from whole human tissue, such as bone marrow, cord blood or a Mobilized Leuko Pak. In terms of HSC percentage and cell counts, the donor to donor variability is intrinsic and significant. Therefore, accurately counting HSCs in the whole tissue is critical for researchers to improve the efficiency of their experiments. AllCells has developed a routine and qualified single-platform flow cytometric method for enumeration of CD34+ hematopoietic stem cells in whole tissue products.
Based upon International Society of Hematotherapy and Graft Engineering (ISHAGE) industry standard guidelines for staining and gating, the assay generates absolute counts for viable white blood cells and CD34+ stem cells within a given tissue. The enumeration data is delivered along with results from a reference sample, to ensure accuracy. Customers can combine this assay with AllCells Bone Marrow, Mobilized Leuko Paks, and Cord Blood products to understand and compare the quality of AllCells collections across donors.

Assay Technical Features

PlatformMulti-color flow cytometry counting assay (BD Trucount™). ISHAGE standards require acquisition of 100 CD34+ events and 75,000 CD45+ events
AnalytesCD34, CD45, SSC, FSC, 7AAD (viability)
InstrumentBD FACSCanto™
ControlsCD Chex level 2 reference samples Streck™
ReadoutsViable CD34+ cells/µL, Viable WBC, CD34+ % Viablity, WBC % Viability, CD34 % of sample
CV< 5% for all readouts
Tissue TypesAllCells Bone Marrow, Mobilized Leuko Paks, and Cord Blood








Gating strategy for enumerating CD34+ T cells: A. CD45 vs SSC plot isolates major white blood cell populations (CD45+) by granularity. B. 7AAD vs SSC plot isolates viable cells, by exclusion of 7AAD. C. CD34 vs SSC plot identifies events with high CD34+ expression. D. CD45 vs SSC plot limits CD34+ events to those with dim CD45 expression

Sample of Reported Data

Event counts are translated into absolute counts and percentages, which are included in the data report.

Viable CD34+ cells/µL2485.6
Viable WBC (CD45+) x103/µL304.9
CD34+ Viability (%)100
WBC CD45+ Viability (%)99.7
CD34 % of sample0.82