I transfected sf9 with PCR-verified bacmid and saw all the signs of infections during transfection and baculovirus amplication of P1 and P2, but I could not see the specific band by SDS-PAGE (Ni NTA purification) for P3 virus infected cell lysates. And, the PCR of purified Bacmid gives only a specific band of expected size,without a 300bp band.The cells are low-passage healthy ones.