Part II: Identification of Proteins with MALDI-TOF
Target S ample D eposition Classic Dry Liquid Droplet Method Step I: Preparation of semi-saturated cyano-4-hydroxycinnamic acid (approximately 5 mg / ml): Dissolve α-cyano-4-hydroxybenzoic acid in 300 μl of 1: 1 acetonitrile / TFA solution (ultrasonication for 10 min) . C entrifuge the liquid for several seconds to obtain t he supernatant. Add 200 μl of the supernatant to a microcentrifuge tube, and add the same volume (200 μl) of a 1: 1 acetonitrile / TFA solution t o prepare a semi-saturated α-cyano-4-hydroxycinnamic acid. Step II: Take 0.8 μl of digestion solution and 0.8 μl of matrix into a microcentrifuge tube and mix them quickly (avoid crystallization at the tip of the pipette) . Take 0.8 μl of the mixed solution onto the MALDI base . The remaining 0.8 μl of the mixed solution can be dropped on another position of the MALDI base , and the tip of the pipette should not touch the standard. Step III: Let the mixture dry naturally and ...