Figure 1. Intracellular uptake of rhodamine-labeled Bence-Jones proteins (BJP) by MDCK cells and patterns of acidification with acridine orange. A, MDCK cells after 60 min of incubation with neutral BJP labeled with rhodamine. B, MDCK cells after 60 min of incubation with acidic BJP labeled with rhodamine. C, MDCK cells after incubation for 30 min with neutral BJP and acridine orange. D, MDCK cells after incubation for 30 min with acidic BJP and acridine orange. Bars = 5 µm.