Extraction and proteome analysis of liver tissue interstitial fluid.

Tissue interstitial fluid (TIF) forms the interface between circulating body fluids and intracellular fluid. Pathological alterations of liver cells could be reflected in TIF, making it a promising source of liver disease biomarkers. Here, we introduce the method of extracting TIF from mouse liver. We confirm the absence of cellular protein contamination by western blot using organelle specific protein markers including lamin B, cytochrome C, and flotillin-1. Using two-dimensional differential in-gel electrophoresis (2D-DIGE), we demonstrate different profiling patterns among TIFs of liver tissue and hepatocytes. The high solubility and even distribution of liver TIF supports its suitability for proteome analysis. Based on the method introduced here, liver TIF in animal models and clinical samples could be extracted and analyzed for further application in liver disease biomarker discovery.