Antagen’s Lentivirus Titration XpressCard is a rapid lateral flow immunoassay that allows quick confirmation
of useful lentivirus titers* in the packaging supernatants. The test detects lentiviral capsule proteins released
into the packaging supernatant as a surrogate marker to determine whether virus production yields a usable
titer for subsequent infection. This assay takes only 10-15 minutes, compared to the conventional re-infection
based assay that takes2-3 days.
* Users are encouraged to correlate T line intensity with functional titers in their own infection systems, as
different cell types have different susceptibility to lentivirus. In the above example, HEK293 cells were infected
with serially diluted lentivirus packaged supernatants. After 72 hours, ZsGreen-expressing cells were
observed under fluorescence microscope. A dark red line was generated by a dilution containing ~2 x 10^6
IFU/ml (as measured byflow cytometry of transfected HEK293 cells).
We tested the sensitivity of our XpressCards using serial dilution of purified concentrated lentivirus stock with
known titres. The results showed that the detection limit is at 1 × 105 TU/ml or 1 × 104 TU (in 100 μL).
1) Place the cassettes in horizontally.
2) Add 80 ~ 100 μl of packaging supernatant directly to the sample well.
3) Wait for 10 ~ 15 minutes.