Figure 1.

Mouse lung seeding in vivo by GFP human lung tumor cells. (A) GFP-transfected cells selected in 50 nm MTX. Approximately 1.0 × 10⁷ cells were injected into the tail vein of nude mice. (B) The excised mouse lung 7 days after cell injection. Numerous fluorescent small colonies can be visualized on the nude mouse lung, with a size of up to approximately 150 microns. Portions of this lung were then explanted into collagen-sponge-gel-matrix-supported histoculture (Bar = 500 μm.)