Optimal transfection methods and comparison of PK-15 and Dulac cells for rescue of chimeric porcine circovirus type 1-2

Abstract A chimeric porcine circovirus type 1-2 (PCV1-2) infectious DNA clone has low transfection efficiency and exhibits low levels of proliferation. Electroporation and lipofection parameters were optimized for PK-15 and Dulac cells with the purpose of increasing the efficiency for rescuing infectious PCV1-2. Titers of PCV1-2 in Dulac cells were 100-fold higher than those in PK-15 cells following transfection. The electroporation efficiency into Dulac cells was high when three 400 μs pulses at 250 V with 6 μg of plasmid DNA was used, lipofection efficiency was high when the ratio of DNA to transfection reagent was 1:3. The proportion of infected cells was 55.6% compared with 44.2%, for the electroporation and lipofection techniques respectively. Virus titers were higher in Dulac cells, from 10 4.44 to 10 5.32  TCID 50 /mL compared with 10 1.90 –10 3.38  TCID 50 /mL for PK-15 cells. Dulac cells were more permissive to PCV1-2 than PK-15 cells regardless of the transfection technique.