TABLE 2.

Ad-free rAAV titers obtained from large-scale preparations of different vector constructs

rAAV vector	Packaging plasmid	rAAV yield (t.u. [109]/10-cm-diam plate)a	t.u./cellb	Particles (105)/cellc
pdx31-LacZ	pXX2	6.1	1,100	9.4
pdx31-LacZ	pXX10d	3.5	640	NDf
pAB-11	pXX2	5.0	900	8.0
pDD-GFP-Neoe	pXX2	1.1	200	ND
pTRhFIXm1	pXX2	ND	ND	1.2

^aAverage of two experiments using 20 plates (15-cm diameter) of human 293 cells. The rAAVs were purified by double CsCl density gradient purification before measurement of the titers. The titers given are the equivalent titers from a 10-cm-diameter plate of 293 cells (t.u./10-cm-diameter plate = total rAAV titer yielded from 20 15-cm-diameter plates divided by 20 and then divided by 2.25, since the surface area of a 15-cm-diameter plate equals 2.25 of a 10-cm-diameter plate). The t.u. were measured by infecting HeLa cells with Ad at an MOI of 1 and various dilutions of rAAV virus stocks. After X-Gal staining, each blue cell was translated into 1 t.u. 

^bObtained by dividing the total vector titers (t.u.) from 20 15-cm-diameter plates by the total number of 293 cells (approximately 20 × 1.25 × 10⁷ = 2.5 × 10⁸). 

^cObtained by dividing the total particle yields (from DNA dot blot) by the total numbers of cells from which the viruses were made. 

^dAn rAAV packaging plasmid derived from pACG2 by replacing the capsid gene of AAV-2 with that of another parvovirus (27a). 

^eThe yield was determined after three rounds of CsCl density gradient purification. The t.u. of this vector is measured similarly to the t.u. of LacZ vectors except it is based on the number of green fluorescent cells. 

^fND, not determined.