For Immunoglobulin Light Chains, It's Time to Fly

[...]there were discrepancies when their MS results were compared with IFE. Because the authors did not have access to detailed clinical information about these patients, the significance of these discrepancies is unclear. Using the mass spectra of isolated heavy chains is challenging due to variable glycosylation as well as poor ionization relative to the light chains. Because the spectra of the normal polyclonal background may overlap small peaks using MS, some of the problems that currently plague M-component quantification when this occurs using SPE or CZE may still be a problem.