Coupling of Target Analyte Enrichment to MS-Based Quantification
Enrichment of target proteins before MRM has proven useful for reliable quantification in the low microgram per liter range, with several studies showing LOQs below the microgram per liter range (46, 49, 50).
Immuno-MS methods often emulate ELISAs in that antibodies immobilized on various platforms are used for capturing target analytes, with mass spectrometers acting as "secondary antibodies" aiding in subsequent detection and quantification.
An additional study used a similar approach for the quantification of thryroglobulin, a low-abundance protein and established tumor marker for thyroid cancer (56).
SISCAPA and similar approaches demonstrate LOQs in the low microgram per liter range, with apparent quantification of certain proteins at sub-microgram per liter concentrations.
Coupling of Immunodepletion and Prefractionation to MS-Based Quantification
w~) amounts to the systematic enumeration of the quantification principles which separate the admissible scalings (weightings) from the inadmissible ones.
The first objective of the approach is to identify these quantification principles, and this results in the definition of the set ||omega~.
is maximally advantageous for the female jobs, the reverse holds for the quantification which is characterized by d equal to |d.
Secondly, the criterion might be judged inadequate because it does not guarantee that the quantification rules and the policy considerations, on which the definition of ||omega~.
Such a quantification is required, for example, to assess whether a given set of job worths is only marginally biased.