Fig. 2. Comparison of Sal-like protein 4 immunostaining for different antigen retrieval methods. Strong positive staining in the nuclei of tumor cells of germ cell tumor (positive control) is observed in section treated with 30-minute autoclave heating (D), whereas intermediate staining is observed in the consecutive section treated with 12-minute microwave heating (A). Two representative sections from hepatocellular carcinoma also shows an enhanced immunoreactivity in sections treated with 30-minute autoclave heating (E, F), compared to 12-minute microwave method (B, C) (×400).