| 摘要 |
The present disclosure provides compositions and methods for performing analysis on a sample. In some embodiments, methods of validating a reaction of a test sample are provided. In some embodiments, the method comprises reacting a test sample comprising a pH-indicating agent, a molecule of interest and a Multiplexed Control and Relative Quantitation ("MCRQ") standard, which can also be referred to as a standard or "Quantitative Multiplexed Control" ("QMC"), with a propionylating agent and a digesting agent; and introducing the reacted sample into a mass spectrometer, wherein if one or more peaks produced in the mass spectrometer attributed to the QMC are above a selected threshold the reaction is validated for the reacting step. Thus, in some embodiments, the QMC can be used to validate. and/or track enzymatic or chemical modifications to substrate molecules using mass spectrometry as described herein. |
