Concentration of LV vectors by ion exchange chromatography using Mustang Q Acrodiscs. A HYPERFlask vessel-derived LV vector-containing supernatant (500 ml) was adjusted to 25 mM Tris-HCl, pH 8.0, 0.3 M NaCl and loaded onto a Mustang Q Acrodisc (bed volume 0.18 ml) at a flow rate of 10 ml/min for 8 min using an AKTA purifier HPLC (Amersham Pharmacia) and Unicorn 4.0 Software (Amersham Pharmacia). The Acrodisc's membrane was washed with 2 ml of 25 mM Tris-HCl, pH 8.0, 0.3 M NaCl and LV vectors were eluted with a 10-ml gradient ranging from 0.3 to 1.5 M NaCl in 25 mM Tris-HCl, pH 8.0 and 1-ml fractions were collected. Flow through, wash, and eluate fractions were collected using a FRAC 950 collector (Amersham Pharmacia) and the OD at 280 nm was recorded (top panel); mAU = milli-absorbance units. Eluate fractions were immediately processed to analyze vector TU (bottom panel). The total TU for each fraction are presented.