Fig. 2. Expression of tight junction proteins in MDCK-C7 and C11. Western blots and densitometry. 2.5 µg of samples were loaded on SDS gel, electrophoresed, blotted and genuine expression of occludin, claudin-1, -2 and -3 was detected using polyclonal antibodies. Densitometric analysis of western blots was performed using quantification software (see Materials and Methods), Expression of occludin (A) and claudin-3 (D) did not differ significantly, whereas claudin-1 (B) and -2 (C) were lower in C7 (n=4-6).