Fig. 7. Cell sorting of CD41⁺ and CD41^– cells from EB6, yolk sac, AGM, fetal liver and bone marrow cells. (A) Cells from yolk sac, AGM, fetal liver and bone marrow were sorted by flow cytometry according to CD41 antigen expression. The percentages of CD41⁺ and CD41^– cells in one representative experiment are shown. The CD41^– and CD41⁺ gates were slightly different in these various tissues. This is especially true for AGM, where a high autofluorescence is found in CD41^– cells. (B) Content in progenitor cells in the CD41⁺ and CD41^– cell fractions. An immunomagnetic technique was used to separate EB6 into CD41⁺ and CD41^– cell fractions. The results for EB6 cells are the mean of the ten experiments. 9.5 dpc yolk sac (YS) (n=3), 10.5 dpc AGM (n=3), 13.5 dpc fetal liver (FL) (n=5) and bone marrow (BM) (n=5) were purified by flow cytometry according to CD41 expression. The number of progenitors (yield) in each fraction (expressed as percentage) was calculated as the ratio between the numbers of progenitors contained in each cell fractions to the number of progenitors contained in the starting population.