Fig. 7. Dual immunostaining of cytokeratin 18 (green) and cytokeratins 1, 5, 10, and 14 (red) of prostatic epithelia grown in Matrigel. Epithelia (sample C) were grown in the presence of KSFM, KSFM plus 2% serum (K2) or K2 plus primary stroma (S), 20-7 M dihydrotestosterone (D) and 10 ng/ml estrogen (O) for 2 weeks. Cell nuclei in spheroids were counterstained with DAPI (blue). Bar, 80 µm.