Clinical performance of the MAGLUMI Anti-HCV (CLIA) Test for detection of hepatitis C virus antibodies.

BACKGROUND: Hepatitis C virus (HCV) infection screening and diagnosis are critical to control the hepatitis C epidemic. Testing for anti-HCV antibodies (Ab) in blood samples is the first step to screen people who have been infected with the virus. OBJECTIVES: To evaluate the performance of the MAGLUMI Anti-HCV (CLIA) Test for detection of HCV antibodies. STUDY DESIGN: To assess the diagnostic specificity, serum samples from 5053 unselected donors and 205 blood specimens from hospitalized patients were collected. To evaluate the diagnostic sensitivity, 400 positive HCV Ab samples were collected and 30 seroconversion panels were tested. All samples that met the test criteria were tested with the MAGLUMI Anti-HCV (CLIA) Test according to manufacturer's instruction. Results of the MAGLUMI Anti-HCV (CLIA) Test were compared with the Abbott ARCHITECT anti-HCV reference test. RESULTS: The specificity of the MAGLUMI Anti-HCV (CLIA) Test was 99.75% and 100.00% in blood donor and hospitalized patient samples, respectively. The sensitivity of the Test in HCV Ab positive samples was 100.00%. Seroconversion sensitivity was comparable between the MAGLUMI Anti-HCV (CLIA) Test and the reference assay. CONCLUSIONS: The performance of the MAGLUMI Anti-HCV (CLIA) Test makes it suited for HCV infection diagnosis.

Enhanced production of Thermomyces lanuginosus lipase in Pichia pastoris via genetic and fermentation strategies.

This study attempted to enhance the expression level of Thermomyces lanuginosus lipase (TLL) in Pichia pastoris using a series of strategies. The tll gene was first inserted into the expression vector pPIC9 K and transformed into P. pastoris strain GS115. The maximum hydrolytic activity of TLL reached 4,350 U/mL under the optimal culture conditions of a 500 mL shaking flask containing 20 mL culture medium with the addition of 1.2 % (w/v) methanol, cultivation for 144 h at pH 7.0 and 27 °C. To further increase the TLL expression and copy number, strains containing two plasmids were obtained by sequential electroporation into GS115/9k-TLL #3 with a second vector, either pGAPZαA-TLL, pFZα-TLL, or pPICZαA-TLL. The maximum activity of the resultant strains GS115/9KTLL-ZαATLL #40, GS115/9KTLL-FZαATLL #46 and GS115/9KTLL-GAPTLL #45 was 6,600 U/mL, 6,000 U/mL and 4,800 U/mL, respectively. The tll copy number in these strains, as assessed by real-time quantitative PCR, was demonstrated to be seven, five, and three, respectively, versus two copies in GS115/9k-TLL #3. When a co-feeding strategy of sorbitol/methanol was adopted in a 3-L fermenter, the maximum TLL activity of GS115/9k-TLL #3 increased to 27,000 U/mL after 130 h of fed-batch fermentation, whereas, the maximum TLL activity was 19,500 U/mL after 145 h incubation when methanol was used as the sole carbon source.