Advantages of ESI over MALDI in proteomics

[amywy88]

Would anybody be able to tell me what the advantages and disadvantages of using electrospray ionisation over MALDI in proteomic analyss would be?!?!
Thanks

[theprof]

ESI is extremely sensitive but the there is a need for a high degree of purity in the test sample. The presence of non polar solvent buffers for example needs to be avoided at all costs as their presence will reduce the sensitivity of ESI. The mass accuracy of ESI is around 0.01%.

MALDI is far more tolerant of the presence of buffers and the accuracy is again in the region of 0.01%. MALDI excels in the analysis of high molecular mass non-volatile organic compounds. MALDI also produces singly charged molecular ions no matter what the molecular mass of the compound, which allows easy interpretation of the spectra. There is some variation in different machines, but they are all simple to use and are becoming the instrument of choice for most uncomplicated procedures. The need for matrices is sometimes regarded as a drawback not least because the compounds are fairly expensive and tedious to use in practice. However, in a well-organised unit, this shouldn�t be much of a problem.