2021 Volume 67 Issue 6 Pages 589-596
Colony-forming unit (CFU) assay has been used as a regulatory quality test to predict the lympho-hematopoietic reconstitution ability of hematopoietic stem cells in umbilical cord blood units. Nevertheless, the reliability of the test results cannot always be assured because a degree of subjectivity cannot be completely excluded from the criteria used to judge the type and number of colonies on microscopy. To overcome this issue, we evaluated the availability of an automated hematopoietic colony-counter system STEMvisionTM by analyzing the correlation between CFU assay results as determined by two experienced technicians and those determined by this automated system. Stable equipment operation was confirmed through accuracy control using a precision control plate with embedded artificial colonies. We found extremely strong correlations between any two of the three results for total colony numbers (rs > 0.92, p < 1.0 × 10-39) and strong correlations between those for numbers of colony-forming unit-granulocyte/macrophage (rs > 0.79, p < 1.6 × 10-20). These results suggest that this automated colony-counter system may give assay results comparable to those with conventional microscopic visualization, and accordingly warrant consideration for introduction as a standard CFU assay method that enables precision control.
