What solvents and buffers are suitable for performing electrospray analysis?
The mass spectrometer detector is very sensitive and will “see” all ionizable substances in buffers and mobile phases. One must avoid non-volatile salts, in particular: phosphate, sodium (keep to less than 1 mM) and detergents (keep to less than 0.01%, avoid or remove if possible). A detergent concentration of 0.1% variably affect signal response = 60% dependent upon the detergent used. At 1% most detergents eliminated the protein signal. Suitable mobile phases, buffers and solvents should be formulated from the following: water, methanol, acetonitrile, formic acid, acetic acid, trifluoroacetic acid (lowest conc. possible), = 10 mM ammonium acetate, = 10 mM ammonium bicarbonate, = 10 mM ammonium formate, and = 2% triethylamine (good for oligonucleotides). How do I handle and stain one and 2-D gels and excise protein bands/spots for analysis on the micromass q-tof or applied biosystems QStarXL mass spectrometers for protein identification and/or map coverage? Proteins and peptides separ
