CpG oligodeoxynucleotides with negative control, TLR9 ligand [NBP2-26232] - Validation of CpG using the TLR9/HEK 293 cell line. The assay was performed using the NF-kB SEAPorter Assay Kit. The Vector/HEK 293 and TLR9/HEK 293 cell lines were transfected with NF-kB/SEAP reporter plasmid for 16 h. Cells were stimulated with various amounts of CpG for 24 h followed by SEAP assay.