Stabilizer stage selection

In the presence of an appropriate stabilizer, it is possible to halt the nucleation at a certain stage and to obtain colloidal nanoparticles. Besides the appropriate choice of the stabilizer, careful selection of the metal precursor, the reducing agent, and the solvent are also important. Stabilizer and reducing agent have to be soluble in the solvent employed, while it is not necessary that the metal precursor is soluble.Psil... 

The MS techniques described previously for characterization of the final recombinant protein product can be applied at all stages during process development. MS might be used upstream to define clone selection, processing format, and purification steps, and downstream to characterize the final product, ascertain lotto-lot reproducibility, determine stability, and define the formulation of biopharmaceutical molecules. Presented here are some examples found either in the literature or from our own experience in which MS has been found to be a useful or necessary tool. Potential limitations of MS methods are discussed, and when appropriate, other analytical methods are mentioned that can be alternatives to MS and are also efficient tools for biopharmaceutical development. 

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