Kinetics of GPA, CD41, CD34, CD43, and CD42 expression during hematopoietic differentiation of H1 hES cells. Flow cytometric analysis of the expression of GPA (y-axis) and CD41, CD42, CD43, and CD34 (x-axis) was performed in hES cell differentiation culture. Plots represent the evolution of the respective proportions of different cell populations within the GPA-positive cells. The gates identifying cells expressing GPA alone or coexpressing CD41 and GPA were set to include only 7-AAD–negative cells. Gating was settled according the negative controls (not shown). Values in each quadrant are the mean ± SD of 3 independent experiments.