Which dose should I use for my in vitro and in vivo experiments?

As the dose is cell-type-dependent, the dose you use for one cell-type might not give you equal results in another. Therefore, we advise to test and try at least 3 doses of mRNA and determine linearity for the specific cell type you are using. A safe range to stay in for a well-designed mRNA is around 50-70 ng/96-well, although some cells will tolerate up to 200-250 ng per 96-well. At RIBOPRO, we often use 10, 50, and 100 ng to determine the optimal dose. Keep in mind that the dose scales (linearly) with a larger surface of cells.
For in vivo use, the species and the target organ make a huge difference in the recommended dosing. For mice, we generally recommend staying below 1-2ug/25gram animal.