The presence of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) and the permanent integration of HBV DNA into the host genome confers the risk of viral reactivation and hepatocellular carcinoma. Nucleoside/nucleotide analogs alone have little or no capacity to eliminate replicative HBV templates consisting of cccDNA or integrated HBV DNA. Recently, CRISPR/Cas9 technology has bee...

Impurity assays for recombinant protein therapeutics are essential to ensure batch-to-batch consistency and to meet the FDA's criteria for a well-characterized biopharmaceutical. For determination of residual host cell DNA, membrane hybridization assays utilizing radiolabeled DNA probes prepared from the host cell's genomic DNA have traditionally been used for products derivedfrom bacterial exp...

Many cases of Toxoplasma gondii infection have been reported worldwide in non-human primates (NHPs), especially captive New World monkeys. However, few studies on toxoplasmosis Old monkeys conducted. In this study, serological and molecular biological analyses were carried out to look for T. antibodies 13 NHPs from China. was confirmed 8 NHP cases. detected 1/5 4/7 DNA 3/5 5/7 The one ring-tail...

The proper maintenance of the pathways governing cell growth is critical to ensure cell survival and DNA fidelity. Much of our understanding of how the cell cycle is regulated comes from studies examining the relationship between DNA viruses and the mechanisms of cell proliferation control. There are numerous examples demonstrating that viruses can alter the host cell environment to their advan...

Background The introduction of animal origin free (AOF) media has significantly reduced the incidence of adventitious virus contamination in biological production systems. Nevertheless, contamination by the parvovirus Mouse Minute Virus (MMV) remains a continuing challenge. Although infrequent, infection of a fermenter can be catastrophic for a manufacturer, and can also have a potential impact...

    Acyclovir (9-[2-hydroxyethoxymethyl] guanine) is an acyclic nucleoside analogue of guanosine which is a potent and selective antiviral agent. Acycloviris converted to the monophosphate by thymidine kinase the virus-specific form of this enzyme and is subsequently converted to the triphosphate by the host cell kinase. Acyclovir triphosphate inhibits viral DNA-polymerase terminating the chain...

cell free dnas (cfdnas) are small fragments of genomic or mitochondrial dna releasing from cells into the blood stream. the presence of cfdna in the human circulatory system has been shown for the first time in 1948 however, the potential clinical applications of cfdna remained unknown until recent progress in detection and quantification of these molecules by sensitive methods. in this paper, ...

Torque teno sus virus (TTSuV), a member of the family Anelloviridae, is a single-stranded, circular DNA virus, widely distributed in swine populations. Presently, two TTSuV genogroups are recognized: Torque teno sus virus 1 (TTSuV1) and Torque teno sus virus 2 (TTSuV2). TTSuV genomes have been found in commercial vaccines for swine, enzyme preparations and other drugs containing components of p...