RESUMO
BACKGROUND: The viability of cord blood is an important measure of product quality. Trypan blue (TB) stain is the most commonly and conveniently used method to measure the viability of the cord blood. Recently, cytometric analysis using 7-Aminoactinomycin D (7-AAD) was introduced. Staining with 7-AAD is more sensitive in detecting cellular damage than staining with TB. In addition to this, 7-AAD allows specific measurement of the viability of total nucleated cells (TNC), mononuclear cells (MNC) and CD34+ cells. In this study, we compared the viability of TNC between the TB and 7-AAD method, as well as analyzing the viability of each cell population. METHODS: From February to July 2010, 102 cord blood units were collected and assessed for the viability of TNC by the TB and 7-AAD methods. The viability of mononuclear cells (MNC) and CD34+ cells was assessed by 7-AAD method. RESULTS: The TB and 7-AAD methods were used to assess the viability of TNC, which was 90.1+/-5.7% and 68.4+/-8.0%, respectively. The viability of MNC and CD34+ cells measured by the 7-AAD method was 91.8+/-4.3% and 93.4+/-5.1%, respectively. CONCLUSION: The TNC viability of 7-AAD method was significantly lower than that of TB method. In 7-AAD method, the viabilities of MNC and CD34+ cells were significantly higher than that of TNC. As those are important prognostic factors and measures for successful engraftment after the transplantation, the measurement of the viabilities of MNC and CD34+ cells by 7-AAD method would be helpful to the quality control of the cord blood product.