Fig. 1.

The 4,4′-MDI-HSA conjugates. a Protein gel analysis (polyacrylamide gel electrophoresis, SDS-PAGE) of the 4,4-MDI-HSA conjugates: lanes 1 = protein standards (the arrows show the positions for human albumin), 2 = 4,4′-MDI conjugate prepared in-solution (i.s.), 3 = 4,4′-MDI conjugate prepared in-vapor (i.v.), 4 = native HSA (no conjugate). b Mass spectrometry analysis (MALDI-TOF-MS) of 4,4′-MDI-HSA conjugates prepared using in-solution (i.s.) and in-vapor (i.v.) methods