ABSTRACT
Coronavirus disease (COVID-19) causes a serious threat to human health. To production of SARS-COV-2 virus-like particles (VLPs) in insect cells for vaccine development and scientific research. The E, M and S genes were cloned into multiple cloning sites of the new triple expression plasmid with one p10 promoter, two pPH promoters and three multiple cloning sites. The plasmid was transformed into DH10 BacTM Escherichia coli competent cells to obtain recombinant bacmid. Then the recombinant bacmid was transfected in ExpiSf9 insect cells to generate recombinant baculovirus. After ExpiSf9 infected with the recombinant baculovirus, the E, M, and S protein co-expressed in insect cells. Finally, SARS-CoV-2 VLPs were self-assembled in insect cells after infection. The morphology and the size of SARS-CoV-2 VLPs are similar to the native virions.
ABSTRACT
Purpose: Detect cytokeratin 19 mRNA(CK-19 mRNA) in nucleated cells in peripheral blood from breast cancer. To establish a diagnostic method for breast cancer metastasis in peripheral blood. Methods: Peripheral blood samples in breast cancer patients (test group, n = 66) and benign tumour in breast patients ( control group, n = 37) were taken. Then, the nucleated cells were separated and total RNA extracted, and CK-19 mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR) technique. Results: Samples were diagnosed CK-19 mRNA positive when 460 bp band appeared in RT-PCR end-product. The positive rate of CK-19 mRNA is 36. 36 % (24/66) in test group . None of the benign tumour breast patients expressed CK-19 mRNA. The difference between the two groups was statistically significant (P
