Fig. 4.
Midi-scale 96 sample protein expression, purification, and characterization. This system utilizes (i) a 96-tube GNF fermentor (Genomics Institute of the Novartis Research Foundation) with O2 aeration at 60 ml scale; (ii) a His MultiTrap HP 96-well plate (GE Healthcare) for Ni-affinity protein purification; and (iii) Zeba™ 96-well desalting spin plate (Thermo Scientific) for buffer exchange. Analytical protein chemistry steps include aggregation screening by analytical gel filtration with static light scattering, homogeneity analysis using Caliper LabChip® 90 system, target validation by MALDI-TOF mass spectrometry, concentration determination by a NanoDrop ND-8000 Spectrophotometer, and NMR screening using a 1.7-mm micro cryo NMR probe.