IHC staining of normal adult testis (A, B) and lung carcinoma (C, D) using mAb LX-CT10.5 (biotinylated secondary Ab, ABC method, DAB chromogen). (A) Formalin-fixed, paraffin-embedded testis tissue with intense nuclear staining of intratubular germ cells and showing no staining of interstitial tissue and intratubular Sertoli cells. (B) Acetone-fixed frozen testis tissue with a similar staining pattern. (C) Lung carcinoma with homogeneous nuclear staining of tumor areas. (D) High-power magnification of lung carcinoma showing negative and intense nuclear staining of cancer cells.