Figure 1

Representative pictures of primary porcine kidney epithelial cells (PKC) at different states of confluence. Pictures show PKC cultures of passage 0, 7 days after isolation with different confluence levels: A, post-confluent (>100% confluence); B, confluent (100% confluence); C, semi-confluent (~70% confluence); the used terms of confluence define the various density states of the cultures, i.e. non-confluent (described as <100% confluence), confluent (a state where the dish is completely covered with cells, described as 100% confluence) and post-confluent (a state, where the maximal cell number is reached, described as >100%). The latter does not mean that these cells grow in multilayers, but that they are able to close ranks more tightly before they stop proliferating due to contact inhibition.