RESUMO
Objective To provide a express plasmid carrier platform that can be in common use for preparation of RNase-resistant RNA standards and controls. Methods A cDNA fragment of MS 2 phage RNA genome, which encodes coat protein and maturase protein, and expression vector pET28b DNA are ligated together with T 4 DNA ligase after digested with HindⅢ and EcoR Ⅰ restriction nucleases. Then, a new expression plasmid carrier pI NCCL is contructed。 The prokaryotic expression was carried out by transform pI NCCL into BL21-DE3 E。Coli. Results A new expression plasmid carrier pI NCCL is contructed successfully. RNase-resistant virus-like particles were obtained after prokaryotic expression of pI NCCL. Conclusion The expression plasmid carrier pI NCCL contructed and prokaryotic expression system can be used as a express plasmid carrier platform that can be in common use for preparation of RNase-resistant RNA standards and controls.