Aphidicolin is a tetracyclic diterpene antibiotic and DNA synthesis inhibitor isolated from Cephalosporium aphidicola. Aphidicolin is reported to specifically inhibit DNA polymerase α and δ via binding to the enzyme, in eukaryotic cells such as the HeLa cell line, without affecting other DNA polymerases. This compound blocks the cell cycle at early S phase and has been reported to be useful for synchronizing cell cycles in cultured eukaryotic cells. This compound is also noted to induce apoptosis in HeLa S3 cells after 18-24 hours of the cell cycle.A novel tetracyclic diterpene antibiotic and also a DNA synthesis inhibitor in eukaryotes