Here we present a protocol to analyze the protein composition of large native protein:protein and protein:nucleic acid complexes from oilseed rape (B. napus) phloem exudate using a 3D polyacrylamide gel electrophoresis (PAGE) approach combining blue native (BN) with two denaturing PAGEs followed by mass spectrometric identification.
Pahlow, S., Ostendorp, A., Krüßel, L., Kehr, J. Phloem Sap Sampling from Brassica napus for 3D-PAGE of Protein and Ribonucleoprotein Complexes. J. Vis. Exp. (131), e57097, doi:10.3791/57097 (2018).