FIG. 3.

Optimization of infection of murine C57BL/6 tracheal cells with Ad-LacZ. Female C57BL/6 mouse tracheal epithelial cells cultured on inserts (see above) were infected with Ad-LacZ at an MOI of 100, in the presence or absence of CaPO₄ precipitates (final concentration of 5.8 mM Ca²⁺ and 0.86 mM PO₄) in MEEM or USG medium. Cells were incubated with this infection medium in a total volume of 250 μl for 45 min at 37°C. Cells were then washed twice with PBS and incubated for 18 to 20 h at 37°C in the absence of media bathing the apical surface. (A) No Ad, USG medium; (B) no Ad, MEEM plus CaPO₄; (C) Ad-LacZ, USG medium; (D) Ad-LacZ, MEEM plus CaPO₄.