Updated project metadata. Serum is an ideal source of biomarkers because of easy accessibility, noninvasiveness, and rapid response to disease. Given that the different clinical manifestation between early phase and late phase of sepsis, the change of serum proteins profile during different phase of sepsis can give insight into predictor for early diagnosis of sepsis. In this study, differential serum proteins were screened in mice treated with lipopolysaccharide (LPS) for 2 h, 24 h and controls using free-labeling coupled with two-dimensional liquid chromatography and tandem mass spectrometry (2D LC-MS/MS) technique.