Validation of the LV.FLPe^NLS+/−.PurR/LV.GS.GpLuc.v1-based cell fusion assay system.

<p>(<b>A</b>): Luminometric analysis of culture medium of myoblasts^GS.GLuc co-cultured with myoblasts-FLPe^NLS+ (+) or with myoblasts-FLPe^NLS− (−) at the indicated ratios. At 72 h after cell seeding, the culture fluid in each well was replaced by fresh culture medium with (growth conditions, no differentiation) or without (differentiation conditions) serum. Nighty-six h later the culture media were collected and subjected to luciferase activity measurements. Bars represent mean ± standard error of the mean (n = 3). (<b>B</b>): Fold change in luciferase activity calculated on the basis of the data presented in (A). For each culture composition the average light production under growth conditions was the denominator and the mean of the RLUs produced under differentiation conditions was the numerator. RLUs, relative light units; MBs^GS.GLuc, myoblasts^GS.GLuc; MBs-FLPe, myoblasts-FLPe; NLS, nuclear localization signal.