HIV-1, HCV and HBV seronegative window reduction by the new Roche cobas TaqScreen MPX test in seroconverting donors.

Background: By shortening the pre-seroconversion window in the viral screening of donated blood, nucleic acid amplification testing greatly improves safety and efficiency, particularly when combined with multiple target detection and maximal automation.

Objectives: Evaluation of seronegative window reduction during HIV-1, HCV and HBV infection by the novel cobas TaqScreen MPX test for simultaneous nucleic acid detection of HIV-1 (groups M and O), HIV-2, HCV and HBV using the cobas s 201 system.

Study Design: Testing of HIV-1, HCV, and HBV seroconversion panels (20 each) using the cobas TaqScreen MPX test versus reference immuno- and nucleic acid technology assays.

Nuclease-resistant single-stranded DNA controls for nucleic acid amplification assays.

Molecular diagnostic tests based on the PCR or alternative nucleic acid amplification technologies are commonly used for pathogen screening at blood drawing centers. Contrived process surveillance using test-specific external and internal controls is critical for the efficient leverage of PCR power. We describe here novel control constructs for use in nucleic acid amplification assays for pathogens with a single-stranded DNA genome, e.

Quantification of parvovirus B19 DNA using COBAS AmpliPrep automated sample preparation and LightCycler real-time PCR.

The COBAS AmpliPrep instrument (Roche Diagnostics GmbH, D-68305 Mannheim, Germany) automates the entire sample preparation process of nucleic acid isolation from serum or plasma for polymerase chain reaction analysis. We report the analytical performance of the LightCycler Parvovirus B19 Quantification Kit (Roche Diagnostics) using nucleic acids isolated with the COBAS AmpliPrep instrument. Nucleic acids were extracted using the Total Nucleic Acid Isolation Kit (Roche Diagnostics) and amplified with the LightCycler Parvovirus B19 Quantification Kit.

Seroprevalence study of herpes simplex virus type 2 among pregnant women in Germany using a type-specific enzyme immunoassay.

In a German seroepidemiological study to determine the proportion of pregnant women infected with herpes simplex virus type 2 (HSV-2) and at risk of transmitting the infection to the newborn during delivery, IgG antibodies to HSV-2 in 1999 sera collected from pregnant women in 1996-1997 were measured using an automated type-specific enzyme immunoassay (Cobas Core HSV-2 IgG EIA; Roche Diagnostics, Switzerland). The seroprevalence of HSV-2 was 8.9%, and control studies with a type-common HSV assay measuring antibodies to HSV-1 and HSV-2 revealed that 20.

Protective effect of vaccination with a combination of recombinant surface antigen 1 and interleukin-12 against toxoplasmosis in mice.

We studied the immune response induced in mice by recombinant Toxoplasma gondii surface antigen 1 (rSAG1) protein, alone or combined with interleukin-12 (IL-12) as an adjuvant, and the protective effect against toxoplasmosis. Immunization with rSAG1 alone induced a specific humoral type 2 immunity and did not protect the animals from infection. In contrast, immunization with rSAG1 plus IL-12 redirected humoral and cellular immunity toward a type 1 pattern and reduced the brain parasite load by 40%.

The soluble glycoprotein of vesicular stomatitis virus is formed during or shortly after the translation process.

Gs protein is a shorter, soluble form of the viral G protein of vesicular stomatitis virus (VSV) lacking the membrane-anchoring domain. Production of Gs protein appears to be a general property of VSV because infection of BHK-21 cells by five different isolates of the VSV serotype Indiana led in all cases to the synthesis of Gs protein. Moreover, it is formed in a variety of eucaryotic cell lines after VSV infection.