[Comparison of sorting of fluorescently and magnetically labelled dental pulp stem cells]

Stem cells are present in many tissues, such as dental pulp. Stem cells can be easily isolated from dental pulp because third molars are often removed from patients. Stem cells could be separated from the tissue derived heterogeneous cell population. There are two main methods to separate a cell type from the other ones: the fluorescence activated cell sorting (FACS) and the magnetic activated cell sorting (MACS). The aim of this study was to compare these methods' effect on cell surviving and population growth after sorting on dental pulp cells. The anti-STRO-1 antibody was used as primary antibody to specifically label stem cells. Two secondary antibodies were used: magnetic or fluorescent labelled. We sorted the cells by MACS or by FACS or by combination of both (MACS-FACS). Our results show that the effectivity of MACS and FACS sorting are comparable while of MACS-FACS was significantly higher (MACS 79.53 ± 5.78%, FACS 88.27 ± 3.70%, MACS-FACS 98.43 ± 0.67%). The cell surviving and the post-sorting population growth, on the contrary, are very different. The cell population is growing on first week after MACS but after FACS did not. Moreover, after MACS-FACS, on first week the cell number of population decreased. Taken together, our results suggest to use MACS instead of FACS, at least in case of sorting dental pulp stem cells with anti-STRO-1 antibody.