Present status and future prospect of accreditation of proficiency testing provider in the area of laboratory medicine in China / 中华检验医学杂志

The accreditation of Proficiency Testing Provider ( PTP) has gone through more than a decade in China.Over the past ten years, from nonexistence to existence, the domestic PTPs in the area of laboratory medicine have gradually standardized and developed.By reviewing the international and domestic practice, this paper gives an outline of the present status of the accreditation of PTP in the area of laboratory medicine, explores the difference with other countries, the main problems and some suggestions for improvement, and makes a prospect of the development of the accreditation of PTP in the area of laboratory medicine in China.

Cloning, Expression, Purification of a Fusion Protein of SARS-CoV Nucleocapsid and Spike Protein Fragments and Its Immunological Characteristics / 中国生物化学与分子生物学报

The spike (S) and nucleocapsid (N) proteins, which are responsible for viral binding to cell surface receptors and the formation of ribonucleoprotein complexes during virion assembling, are major structure proteins of severe acute respiratory syndrome coronavirus (SARS-CoV). The expression of recombinant protein may give more accurate result for detecting SARS-CoV infection. A novel fusion protein,comprising of two fragments of N and S proteins from SARS-CoV, was prepared. Our computer-assisted analysis suggested that the immunodominant domains were located in the amino acid residues 1-227 of N protein and 450-650 of S protein, further the fusion of the two fragments did not change the immunochemical characteristics. The complementary DNA(cDNA) encoding N1-227 fused with S450-650 was obtained by sequence overlapping extension (SOE), and named NLS. It was cloned into pET-28a ( + ), an expression vector for His-tag fusion protein. This new constructed fusion protein was prokaryotic expressed in E. coli,and purified by metal chelate affinity chromatography with the purity over 95 %. The purified fusion protein was identified by anti-His monoclonal antibody and convalescence SARS patients serum. The NLS protein based ELISA showed that NLS maintained appropriate antigenicity and specificity to react with the sera of convalescent SARS patients. The functional NLS protein were successfully expressed and purified. And the fusion protein based ELISA can be used for detection of antibodies (Abs) against the S and N proteins of SARS-CoV. It may provided a novel diagnostic tool and have the potential application in developing of anti-SARS vaccine.