title: The proper criteria for identification and sorting of very small embryonic-like stem cells, and some nomenclature issues.
abstract: Evidence has accumulated that both murine and human adult tissues contain early-development stem cells with a broader differentiation potential than other adult monopotent stem cells. These cells, being pluripotent or multipotent, exist at different levels of specification and most likely represent overlapping populations of cells that, depending on the isolation strategy, ex vivo expansion protocol, and markers employed for their identification, have been given different names. In this review, we will discuss a population of very small embryonic-like stem cells (VSELs) in the context of other stem cells that express pluripotent/multipotent markers isolated from adult tissues as well as review the most current, validated working criteria on how to properly identify and isolate these very rare cells. VSELs have been successfully purified in several laboratories; however, a few have failed to isolate them, which has raised some unnecessary controversy in the field. Therefore, in this short review, we will address the most important reasons that some investigators have experienced problems in isolating these very rare cells and discuss some still unresolved challenges which should be overcome before these cells can be widely employed in the clinic.
authors.affiliation: 1 Stem Cell Institute at the James Graham Brown Cancer Center, University of Louisville , Louisville, Kentucky.
authors.forename: Malwina
authors.initials: M
authors.lastname: Suszynska
authors.forename: Ewa K
authors.initials: EK
authors.lastname: Zuba-Surma
authors.forename: Magdalena
authors.initials: M
authors.lastname: Maj
authors.forename: Kasia
authors.initials: K
authors.lastname: Mierzejewska
authors.forename: Janina
authors.initials: J
authors.lastname: Ratajczak
authors.forename: Magda
authors.initials: M
authors.lastname: Kucia
authors.forename: Mariusz Z
authors.initials: MZ
authors.lastname: Ratajczak
mesh_terms: D053687:Adult Stem Cells / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D016477:Artifacts; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation; D019070:Cell Lineage / Q000502:physiology; D002469:Cell Separation / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D048429:Cell Size; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism; D004900:Erythroblasts / Q000166:cytology / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D051379:Mice; D039902:Multipotent Stem Cells / Q000166:cytology* / Q000378:metabolism
chemical_list: D015415:Biomarkers