Figure 4.

NSCs injected into tail vein “target” intracerebral gliomas. Paradigm 5 is illustrated. (A–C) Progressively higher power views of representative 10-μm sections through the brain 4 days after NSC injection, processed with X-Gal histochemistry (A) and anti-β-gal immunocytochemistry (B and C) to identify donor NSCs and counterstained with neutral red to delineate the tumor border. (The β-gal immunoproduct, in addition to providing independent identity confirmation, typically fills cells and processes much better than X-Gal.) At low power (A), X-Gal⁺ NSCs (representative X-Gal precipitate enlarged in Inset) are distributed throughout the tumor but not in surrounding normal tissue. Sister sections, reacted with an anti-β-gal antibody and visualized at higher power in B and further magnified in C confirm the presence of donor-derived cells (arrow) within the tumor. (Scale bar: A, 25 μm, 20 μm in B, and 12 μm in C.)