Table 1

Evaluation of the different titration methods

RNA c/ml

TU/ml

pg p24/ml

TU/pg

TU/RNA

Cell factories

CH-eGFP-WS

2.68 ± 0.38 × 10¹⁰

2.23 ± 1.10 × 10⁹

9.8 ± 5.3 × 10⁶

228

0.0832

Culture dishes

H-eGFP

5.63 ± 0.50 × 10¹⁰

5.05 ± 4.9 × 10⁷

4.67 ± 4.5 × 10⁶

11

0.0009

H-eGFP-WS

3.83 ± 2.25 × 10¹⁰

2.92 ± 2.5 × 10⁸

4.83 ± 4.70 × 10⁶

60

0.0076

CH-eGFP-WS

2.73 ± 1.59 × 10¹⁰

1.68 ± 1.3 × 10⁹

4.79 ± 3.45 × 10⁶

351

0.0615

The lentiviral vector CH-eGFP-WS was produced in cell factories and concentrated by centrifugation as described before [8]. Three independent RNA extractions were carried out on this vector and RNA equivalents were determined by RT-qPCR. Mean values ± standard deviation are shown. Next, three lentiviral vectors with different transfer plasmids, H-eGFP, H-eGFP-WS and CH-eGFP-WS, were produced in parallel in cell culture dishes. RNA equivalents (RNA/ml), transducing units (TU/ml) and p24 concentrations (pg p24/ml) were determined by RT-qPCR, titration and ELISA, respectively. The TU/pg and TU/RNA value indicate the specific activity of the vector constructs and correlate well with the vector backbones. The data represent the mean values ± standard deviation of three independent productions per lentiviral vector.

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