TABLE 2.
Concentration of alphavirus pseudotypes
| Envelope | eGFP titer (% recovery after concn)b
|
||
|---|---|---|---|
| Unconcentrated | After centrifugation ata
|
||
| 105 × g/1.5 h | 3000 × g/8 h | ||
| VSV-G | 59 | 220 (93.2) | 180 (76.3) |
| RRV | 7.6 | 82 (53.9) | 41 (27.0) |
a
Alphavirus pseudotypes were concentrated 20-fold and HIV-1(VSV-G) was concentrated 4-fold by centrifugation at 10,000 or 3,000 × g Virus was titrated on to 293T cells with 8 μg of Polybrene/ml, and eGFP expression was assayed by FACS.
b
Titer is expressed as 105 IU/ml. Percent recovery [(100 × titer after concentration)/(concentration factor × unconcentrated titer)] is shown in parentheses.