RNA in situ hybridization of VEGF mutant ES cultures.

Day 8 cultures were fixed and processed for in situ hybridization as described in “Materials and methods.” Cultures were hybridized with an antisense PECAM probe (A, C, E, G) or an antisense flk-1 probe (B, D, F, H). (A, B) Wild-type (+/+) VEGF ES cultures. (C, D) Hemizygous (+/−) VEGF mutant ES cultures. (E-H) Null (−/−) VEGF mutant ES cultures. Magnification, (A-F) 50×, (G-H) 100×.