Quality Control Testing

Flow CytometryA flow cytometer is used to determine the identify and size of specific cell populations in the product. Example: CD34 EnumerationThe CD34 molecule is a cell surface antigen which exclusively identifies stem cells of the hematopoietic system. The flow cytometer is used to enumerate this CD34 marker and identify the size of the stem cell population in order to calculate the target dose.

Determining Cell Viability Viability (proportion of living and dead cells) is an important indicator of the overall potency of the stem cell

product. Two methodologies are used to determine viability.• Trypan Blue Dye Exclusion: Dead cells appear blue under the microscope as their damaged membranes allow

trypanblue dye to pass through, while live cells are colorless.• Flow Cytometry: Fluorescent compounds penetrate dying and dead cell membranes and insert into the DNA.

The flow cytometer is able to accurately identify these dyed cells, and determine the viability of specific cell populations.

ABO / RH TypingIn order to help confirm identity, units are blood typed prior to processing.

Determining the Total Viable Nucleated Cell Count An automated hematological analyzer is utilized to measure and differentiate cell types in the stem cell product. This information is used to assess the processing efficacy and quality of the product. The white blood cell count is often used as a release criteria, or component of the cell dose calculation.

14 Day Product SterilitiesAn automated microbial detection system is used to monitor product sterilities. Microorganisms present in the cultures release carbon dioxide, triggering the instrument to alert the user that there is a positive sample.