TABLE 6.

Comparison of different methods used for purification of retrovirus vectors

Method (Reference[s])	Yield (%)	Contaminants in purified vector supernatants		Viral titer (CFU/ml)	Large-scale processing	Cost
		Proteins (mg/ml)	DNA (μg/ml)
This work	56	<0.007	<2.5 × 10−5	1.2 × 106	Easy	Low
Ultra-filtration (12)	65	3.2	42.2	1.0 × 105	Difficult	High
Hollow fiber filtration (13, 15)	50-80	Large-molecular contaminants are co-concentrated with viral vectors		∼5.5 × 107	Difficult	Medium
Chromatography (12)	10	0.09	3.78	1.6 × 104	Easy	Low
Centrifugation (4, 6, 7)	50-97	Significant cosedimentation of contaminants, especially those corresponding in size to known viral proteins, including CA, integrase, and matrix proteins		106-1.1 × 108	Difficult	Medium