6.1 Mass spectrometry
Mass spectrometry (MS) determines protein molecular weights by analyzing mass-to-charge ratios (m/z) in a three-step process: converting molecules into gas-phase ions, separating ions based on m/z ratios, and quantifying ion quantities for specific m/z values. Common ionization methods include electrospray-ionization, matrix-assisted laser desorption ionization (MALDI), and surface-enhanced laser desorption/ionization (SELDI) [62].
GF1, IGF2, A2GL, and other blood proteins have potential as breast cancer biomarkers, with MS used to detect and quantify them along with interleukin-12, prostate-specific antigen (PSA), and human growth hormone in human samples. MS also reveals drug administration and metabolite distribution within the body, aiding in analyzing novel treatments and therapeutic processes [63].