Quantification of vector copy number in tissues of hemophiliac mice after intravenous injection of SIN LVs expressing bioengineered FVIII constructs. Liver, spleen, heart, lung, and kidney tissue were taken from mice killed at approximately 250 days after neonatal injection of LVs expressing SQ FVIII, SQ FVIII Fugu B, SQ FVIII N6, SQ FVIII (co), SQ FVIII Fugu B (co), and SQ FVIII N6 (co). Genomic DNA was extracted and viral copy number determined using quantitative PCR. Line represents the mean of all points. No significant difference in copy number was observed between any vector group (P > .1, Bonferroni simultaneous test).