ABSTRACT
Many of the concepts of stem cell identification and isolation have been elaborated through research into hematopoietic stem cells and this has relied heavily upon the use of combinations of antibodies against cluster of differentiation antigens. Since side population characteristics are not restricted to stem cells, the property is best utilized as means to refine stem cell identification and isolation in combination with other parameters, especially surface marker staining. The DNA replication and proliferation characteristics of stem cells have also been employed both to identify them, especially in situ, and infrequently as a means of isolation. Cloned versions of these fluorescent proteins can be used either in isolation as reporters of gene expression and cell location or fused to proteins of interest as a way of tracking their location, stability, and so on. The characteristics of cells isolated by the methods described in the previous section, and in particular assessment of features that define their stemness, can be explored.
