Stem cells, which resemble white blood cells with very small nuclei and cytoplasm, have the capacity to differentiate into any of the mature blood cells. Very primitive, pleuripotent stem cells have the capability of differentiation into other cell types, such as heart and nerve, as well.(1) Since 1968, stem cells in bone marrow have been used in treatment of leukemias, lymphomas, and immune deficiency disorders.(2) More recently, cord blood and peripheral blood stem cells have been utilized. Currently, the main sources for stem cells are bone marrow, cord blood, and peripheral blood.
Chemotherapy and radiation used in cancer therapy have an adverse effect on bone marrow. Stem cells have been used to repopulate a patient’s bone marrow subsequent to high-dose chemotherapy or radiation treatments. The choice of the source of stem cells is often based on such factors as the health of the bone marrow cells or the difficulty of stem cell collection. For example, harvesting stem cells from the bone marrow may require general anesthesia. Peripheral blood stem cells are collected, over several days, by the apheresis process. Also, if the patient’s bone marrow contains cancerous cells, sometimes healthy cells may be obtained from peripheral blood. Often the stem cells, regardless of source, are frozen for future cellular transplantation. Upon thawing, these cells must be assayed for both percentage viability and concentration.
Many facilities employ the manual, trypan blue method for these measurements. The Beckman Coulter Vi-CELL™ XR (Figure 1) automates the manual trypan blue vital dye cell viability method. The instrument removes the subjective variation among operators inherent in manual cell enumeration using a microscope. This Application Bulletin demonstrates that stem cell percentage viability and concentration, from the above-mentioned sources, may be measured accurately and precisely using the Beckman Coulter Vi-CELL XR.