Fig. 5. Time-dependent protein expression of the basolateral uptake systems Ntcp (A) and Oatp1b2 (B) in cultured rat small hepatocytes. Cells were cultured for up to 9 weeks. They were fixed at weeks 1 (a,b), 5 (c,d), 7 (e,f) and 9 (g,h) with 4% paraformaldehyde in the presence of Triton X-100 and subsequently processed for immunofluorescent transporter localization. (a,c,e,g) Phase-contrast microscopy pictures. (b,d,f,h) Confocal laser-scanning microscopy pictures. Scale bars, 40 µm.