Ni-NTA chromatogram and SDS PAGE analysis. TEV digest: 10 µL sample + 10 µL 2x SDS sample buffer, loaded 2.0 µL. Fractions of interest: 10 µL sample + 10 µL 2x SDS sample buffer, loaded 5 µL. Green boxes: Collected flow through (Fractions 20-21, 16 mL), and uncleaved His7-TEV-RAP protein eluted from the Ni-NTA column (Fractions 33-34).