Fig. 2

Immunohistochemical staining of lung adenocarcinoma. A Aquaporin-4 (AQP-4), (B) CD68, (C) AQP4 + CD68, (D) hematoxylin and eosin (H-E) stain. The biopsied specimen was fixed in 10% buffered formalin. After embedding the tissue in paraffin, 3–4-μm-thick sections were prepared. Immunohistochemical study was performed using antibodies against AQP-4 (4/18: sc-32,739, monoclonal, 1:100: Santa Cruz Biotechnology, Dallas, TX) and CD68 (bs-0649R, polyclonal, 1:500: Thermo Fisher Scientific, Waltham, MA). After digital recording of the fluorescent signals, the coverslips were removed, and the same slide was subjected to H-E staining to yield the bright-field counterpart of the fluorescence images, similarly recorded by the same equipment. The scale bar represents 20 μm. Some CD68-positive macrophages were positive for the AQP-4 staining