Table 1.

Vector concentration by single-step ultracentrifugation

Vector titres were determined on 293T cells.

Vector	Unconcentrated (IU ml−1)*	Concentrated (IU ml−1)	% Recovery
MoMLV	(1.57±0.11)×107	(4.22±0.22)×109	89.48±3.08
DHIV-101	(1.55±0.10)×107	(4.34±0.27)×109	93.33±0.89
HR-cPPT	(5.86±0.41)×106	(1.49±0.13)×109	84.46±1.39

*Vector-containing supernatant was collected every 24 h for 3 days post-transfection from a representative transfection experiment, which was performed in triplicate for each vector type.