Identification and quantification of very small embryonic-like (VSEL) stem cells in fresh umbilical cord blood

Abstract

The present study aimed to identify, quantify and compare the quantities of very small embryonic-like (VSEL) stem cells in the two main fractions of fresh umbilical cord blood (UCB). To do this, UCB obtained during caesarean section underwent gradient centrifugation. Nucleated cells isolated from the two main fractions – the mononuclear cell layer above the gradient, and the red blood cell pellet below the gradient – were immunofluorescently labelled to identify the VSELs (CD45−/CD133+/SSEA4+). These two cell fractions were then analysed via multiparameter sorting on a flow cytometer and the quantities of positively stained cells were compared.