Moving forward in colorectal cancer research, what proteomics has to tell

Figure 4 Principles of SELDI-TOF MS. The application of sample from to an eight-spot array with hydrophilic, hydrophobic, cationic, anionic or immobilized-metal affinity capture chromatography surface (black colour). The addition of an appropriate binding buffer (purple colour). On-chip sample purification using one or more wash buffers (grey colour). The application of energy-absorbing matrix for the absorption of laser energy (empty colour). Laser irradiation desorbs bound proteins and positively ionizes them. Owing to the electric field, they migrate in the mass analyser: (small diamond) and multiply charged proteins (oval) faster than large and single-charged ones (triangle). Thus, the proteins are separated. Time of flight (t) is proportional to protein mass per charge.