The data for all three solutions showed that the Mobius mixer was able to homogeneously mix powder-liquid solutions at the tested concentrations in under 20 minutes. The data for the 10 mM PBS showed a decline in pH values after 30 minutes, but this was most likely due to chemical changes in the solution (e.g., dissolution of atmospheric carbon dioxide) that can be attributed to the weak buffering capacity of the solution.
The drop in pH was not a mixing phenomenon, and the mixture remained completely mixed even during the pH change within the solution. The figures clearly show that a homogeneous solution is achieved in 20 minutes or less for all three tested solutions.
Visual inspection of the process containers during mixing and draining of the system confirmed that, for the tested concentrations, the powders did not settle on the bottom or attach to the sides of the process container.
Due to the variation in solid-liquid mixing applications, it is recommended that each specific liquid-powder application be evaluated individually prior to implementation. However, the information presented in this document can be used as a reference for various buffer, media, and protein solutions.