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Flow Cytometry Services


Using cells in suspension, Caltag Medsystems' immunophenotyping service allows the characterisation of extracellular molecules using fluorescently-labelled antibodies. These include MHC/HLA typing, cancer cell analysis (focusing on haematological malignancies), and other custom analyses.

To discuss your immunophenotyping requirements please contact us today +44 (0) 1280 827840 or email techsupport@caltagmedsystems.co.uk.

CD34 Enumeration of Fresh Tissue Products

CD34+ hematopoietic stem cells (HSC) are human cells used in developing cell and gene therapies. Very limited numbers of HSCs can be collected from whole human tissue, such as bone marrow, cord blood or Mobilized Leuko Paks, and between donors the variability of HSCs within samples is significant. Accurate counting of CD34+ HSCs in samples is thus critical and allows researchers to improve the efficiency of their experiments.

AllCells, a supplier of fresh bone marrow, cord blood and Mobilized Leuko Paks 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.

Platform Multi-color flow cytometry counting assay (BD Trucount™). ISHAGE standards require acquisition of 100 CD34+ events and 75,000 CD45+ events
Analytes CD34, CD45, SSC, FSC, 7AAD (viability)
Instrument BD FACSCanto™
Controls CD Chex level 2 reference samples Streck™
Readouts Viable CD34+ cells/ÁL, Viable WBC, CD34+ % Viablity, WBC % Viability, CD34 % of sample
CV <?5% for all readouts
Tissue Types AllCells 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/ÁL 2485.6
Viable WBC (CD45+) x103/ÁL 304.9
CD34+ Viability (%) 100
WBC CD45+ Viability (%) 99.7
CD34 % of sample 0.82

For further information about Flow Cytometry services please contact us today +44 (0) 1280 827840 or email techsupport@caltagmedsystems.co.uk to discuss your requirements.