FIG. 5.
In vivo half-lives of intravenously injected canine- and human PCL-produced retroviral vectors in macaques. Equal titers (∼3 × 109 BCFU) of DA- or HA-produced β-Gal vector were injected intravenously into macaques. There were two animals per group. Animals A and B received canine PCL (DA) vector; animals C and D received human PCL (HA) vector. At the times indicated, blood was drawn, and sera were prepared and frozen. The biological titer in serum samples was determined by a standard BCFU assay on tissue culture HT1080 cells. Macaques A and B had undetectable titers (shown here as 10 BCFU/ml).