Development of a novel assay to evaluate the functional potential of umbilical cord blood progenitors

Abstract

These results support the notion that the HALO assay is a reasonable approach for measuring the functional potential of hematopoietic progenitors in UCB. Moreover, because the final readout for the HALO assay is instrument based, unlike the CFC assay, which requires a subjective enumeration of colonies, the HALO assay may be more amenable to standardization.

CD34+ cell responsiveness to stromal cell–derived factor‐1α underlies rate of engraftment after peripheral blood stem cell transplantation

“…Interestingly, this assay has been criticized because it is based on a subjective visual assessment that cannot be calibrated or standardized and does not directly measure proliferation. Recently, a new assay that relies on instrument‐based measurement of intracellular ATP concentration has been shown to be directly proportional to the proliferation status of cells 29 and to predict engraftment outcome 30 . It may replace the colony‐forming cell assay in the future but awaits full validation.…”

Potency, Proliferation and Engraftment Potential of Stem Cell Therapeutics: The Relationship between Potency and Clinical Outcome for Hematopoietic Stem Cell Products

“…These expectations included "standardized methodologies, reproducibility with limited variability between testing sites, automated testing outputs, high throughput for UCB banks, rapid turnaround time and single sample tests for transplant centers". All of these expectations have been met by the assay described above and in detail elsewhere [14,15,61]. Yet, the NMDP has not yet exercised its expectations within the framework of its own guidelines.…”

“…This readout technology has been incorporated into a stem cell quality assay [13] and two potency assays, one developed for lympho-hematopoietic cells (HALO-96 PQR) and one for mesenchymal stem/stromal cells (LUMENESC-96 PQR). Both assays use the same concepts and principles described here to measure potency and quality and defining acceptance limits for releasing the product for use [14,15].…”

“…For stem cells, proliferation ability is equivalent to stem cell "quality". It follows that from the cell dose response used to measure stem cell proliferation potential and potency, it is also possible to measure proliferation ability or "quality" at the same time [14,15].…”

Hematopoietic Stem Cell Potency for Cellular Therapeutic Transplantation

“…Prior to measuring bioluminescence of the samples after culture incubation, an ATP standard curve was performed (Rich & Hall, 2005;Reems et al 2008;Hall & Rich, 2009). Serial dilutions from a 10M stock concentration were prepared so that the final dilutions were 5, 1, 0.5, 0.1, 0.05, 0.01 and 0.005M.…”