Growth potential of porcine kidney cells compared to fetal and ear fibroblasts. PKCm (A, left and middle panel) and PKC2109 (B, left and middle panel) grew rather in islands at P4 on non-coated plates compared to collagen-coated plates where they grew evenly spread. Scale bar = 100 μm. The proliferation assay showed best growth potential on collagen-coated plates with PKCm (A, right diagram) and PKC2109 (B, right diagram). (C) Growth curves of PKCm, PKC2109, PFF26 and PEF0110. Every 12–24 h cell numbers of various cell types were determined. The x-section (exponential growth phase) was used for calculation of population doubling time. PKC2109 and PKCm exhibited the shortest population doubling time compared to PFF26 and PEF0110. (D) Correct karyotype (2n=38) of PKC2109 at passage 71.