Abstract: Methods are provided for detecting insulin-like growth factor-I (IGF-I) variant(s) in a sample. Methods provided herein are further directed to using the detected ion or ions to determine the presence of IGF1 variant(s) in the sample.

Abstract: A processing platform in one embodiment comprises one or more processing devices each including at least one processor coupled to a memory. The processing platform is configured to implement a crosslink identification and validation algorithm for processing multiple levels of mass spectrometry data in order to identify and validate protein-protein interactions within the mass spectrometry data. In conjunction with execution of the crosslink identification and validation algorithm, the processing platform is further configured to obtain mass spectrometry spectra for each of the multiple levels, to apply a header matching filter to identify at least one potential crosslink relating one or more first level spectra and one or more second level spectra utilizing a plurality of third level spectra, and to apply one or more mass validation filters to identify whether or not the potential crosslink is a valid crosslink.