Figure 3.
Flow cytometry analysis for the expression of cell adhesion-related molecules on mouse ES cells in absence or presence of 10−6 M retinoic acid. Undifferentiated ES cells express CD9, ICAM-1, PECAM-1, and SSEA-1. The fluorescence intensity for SSEA-1 ranges from background level to strong in every plot of undifferentiated ES cells. Approximately half of the cells are SSEA-1-negative. The dot-plot patterns of ICAM-1 and PECAM-1 are similar to one another, with double-negative cells comprising 17.6% and 18.9% of the population, respectively. In contrast, almost all of the cells (98%) are CD9-positive. After treatment with 10−6 M retinoic acid, double-negative cells for SSEA-1 and ICAM-1, PCAM-1, or CD-9 clearly increased. The quads were set up on the control's dot-plot.