PECAM/ICAM-2 double-label immunofluorescent antibody staining of VEGF mutant ES cultures.

Day 8 cultures were fixed and stained with rat antimouse ICAM-2 (red) and rabbit polyclonal antimouse PECAM (green) antibodies, along with the appropriate secondary antibodies. Images were photographed with the appropriate FITC (B, E, H) or rhodamine (C, F, I) filters or with a double exposure using both filters sequentially (A, D, G). (A-C) Wild-type (+/+) VEGF ES cultures. (D-F) Hemizygous (+/−) VEGF mutant ES cell cultures. (G-I) Null (−/−) VEGF mutant ES cultures. The arrows in (D-I) point to clumps of cells that stain with the PECAM antibody but not with the ICAM-2 antibody. Magnification, 50×.