Why do I NOT need to create a standard curve for Lenti-X GoStix Plus?

For other commonly used titration kits such as p24 ELISAs and pRT-PCR assays, you always need to compare your test sample to a standard curve that you generate. This is not required for Lenti‑X GoStix Plus because the standard curve for each lot of Lenti‑X GoStix Plus is generated at Takara Bio USA, Inc. and loaded onto the app when you open it and connect your mobile device to the internet. In [...]

Can Lenti-X GoStix Plus be used even in the absence of a smartphone?

Absolutely, however, without scanning the intensity of the band, the result will be qualitative (yes, my prep is good; or no, my prep is not ready) rather than a quantitative titer. In general, a clear band generated by a dilution should contain ~5 x 105 IFU/ml (as measured by flow cytometry of transduced HT-1080 [...]

What happens if I do not wait 10 minutes for the signal to develop?

The test will not give consistent results if the full development time is not observed and you will not be able to accurately compare your result to previously tested samples. A warning within the app will appear if the Skip button is pressed before 10 minutes have elapsed on the [...]

How can harvest time affect the GoStix Value?

The GoStix Value (GV) is proportional to the amount of p24 protein produced, which in turn correlates with the length of the time to harvest. Therefore, a longer harvest time will result in a larger GV (ng/ml p24), assuming that other conditions (e.g., packaging system, transfection method, etc.) are kept constant. The data demonstrated that the ratio between GV and IFU/ml varies depending on the [...]

What factors can impact a GoStix titer?

When using Lenti‑X GoStix Plus (or any other method, e.g., p24 ELISA, or qRT-PCR) to compare titers between different experiments, the following variables must be consistent: lentiviral packaging systems, lentiviral vectors, transfection methods, harvest times, and scanning devices. If any one of these parameters is changed between experiments, we recommend that you re-correlate the GV to [...]