Table 4

Reliability of the titration methods to assess lentiviral vector production quality

packaging plasmid

envelope plasmid

transfer plasmid

RNA/ml

TU/ml

pg p24/ml


+

+

+

6.18 ± 1.71 × 109

1.07 ± 0.53 × 107

4.10 ± 2.05 × 105

+

+

-

below detection limit

below detection limit

2.10 ± 0.64 × 105

+

-

+

2.36 ± 0.63 × 1010

below detection limit

1.27 ± 0.32 × 105

-

+

+

8.04 ± 1.64 × 106

below detection limit

below detection limit


Lentiviral vectors were produced in parallel in cell culture dishes by triple transient transfection with transfer, envelope and packaging plasmids. Omission of a plasmid is indicated. RNA equivalents (RNA/ml), transducing units (TU/ml) and p24 concentration (pg p24/ml) were determined after concentration of LV by low-speed centrifugation. For the CH-eGFP-WS vector, the titer was measured with all three methods. In the absence of the packaging plasmid, encoding for structural proteins, the RNA titer decreased 1000-fold while p24 and TU titers were below detection limit. Omission of the envelope plasmid during the vector production resulted in p24 and RNA titers comparable with those of a normal production albeit with a non-detectable functional titer. Vector production without transfer plasmid only yielded a positive p24 titer. Mean values ± standard deviation for 3 measurements of the same sample are shown.

Geraerts et al. BMC Biotechnology 2006 6:34   doi:10.1186/1472-6750-6-34

Open Data