µSI Process Analyzer System for MAM Sample Prep
The detailed µSI process analyzer fluidic design for MAM sample preparation is described in Figure 1 . It consists of a series of columns, reaction chambers, tubing, liquid redirect valves, a multi-position solvent selector valve, and a syringe pump. Software scripting capabilities enable the µSI process analyzer system to robustly execute the process steps described in Table 1 .
Test samples can be acquired directly from the bioreactor supernatant or purified material. The sample is aspirated into the system through the solvent selector valve and passed through an affinity purification column where the protein of interest is bound, and the sample matrix is removed as column flow-through. The purified protein is then eluted and delivered to a thermostatic incubator where denaturation, reduction, and alkylation reactions occur. This chemically processed sample undergoes buffer exchange and is enzymatically digested in a second thermostatic incubator before chromatographic separation and mass detection.