Figure 1.
The i.p. injection approach in a CD-1 mouse at E15. (A) Methylene blue (10 μl at 0.25%) was injected by a transuterine approach into the fetal abdomen, filling the i.p. cavity. The fetus, placenta, and intact amniotic sac were delivered through a hysterotomy. (B and C) Pattern of β-galactosidase (LacZ) expression in tissues at E18 from CD-1 fetuses injected with 1 × 107 plaque-forming units (pfu) of Ad-LacZ at E15. (B) X-Gal staining is present in the intestine (I), liver (Lv), peritoneum, heart (H), and lungs (L) at E18. (C) Tissue sections, counterstained with nuclear fast red, show LacZ staining of fetal peritoneum and intestinal serosa at E18 (×50 magnification). (D) High-magnification photomicrograph of LacZ-expressing cells in the intestinal serosa (oil lens, ×1,000).