Mesothelial cells (MCs) form a single squamous epithelial cell layer and cover the surfaces of the internal organs, as well as the walls of cavities. The isolation of MCs is of great importance to study their function and characteristics for the understanding of physiology and pathophysiology of the liver. Glycoprotein M6a (GPM6A) was originally identified as a cell surface protein expressed in neurons and recently its expression was reported in epicardium and liver MCs (Wu et al., 2001; Bochmann et al., 2010; Li et al., 2012). Here we describe a method to isolate MCs from the adult mouse liver with anti-GPM6A antibodies. Under the low glucose and serum concentration, primary MCs grow and form epithelial colonies (Figure 1).