Table 1.

Comparison of blood island formation in EBs of flk-1 (+/−) and flk-1 (−/−) ES clones

Clone	Benzidine-positive blood islands per 10 EBs plated
5539 (+/−)	6.13  ± 0.98
5540 (+/−)	5.77  ± 0.71
5547 (−/−)	4.12  ± 0.36
5548 (−/−)	4.48  ± 0.78

Cultures were fixed and stained 11 days after dispase treatment. The difference in number of blood islands between the flk-1 (+/−) and (−/−) is statistically significant (P < 0.02). The differences in number of blood islands between clones of the same genotype are not statistically significant [flk-1 (+/−), P > 0.2; flk-1 (−/−), P > 0.3].