Hbv Dna Quantitation

For quantitation of HBV DNA, a commercial third-generation assay is available from Bayer Diagnostics (VERSANT HBV DNA 3.0). Results of a multicenter evaluation showed that the specificity of this test was 99.3% using 600 HBV seronegative samples at four different sites. Quantitation was possible between 2 x 103 and 1 x 108 copies HBV DNA/mL and the assay proved to be linear throughout its entire dynamic range. Mean coefficients of variations of 7.5% and 13.6% were established for intra- and interassay imprecisions, respectively. Furthermore, studies revealed that HBV DNA concentrations obtained by bDNA 3.0 differed by less than threefold from the expected values for HBV isolates of genotypes A to F, suggesting that quantitation is not significantly affected by HBV genotypic variability.[7]

Because HBV DNA quantitative units reported by the various commercially available assays currently do not represent the same actual amount of HBV DNA in a given sample, these tests cannot be used interchangeably in the clinical laboratory. Therefore, like bDNA 3.0, all quantitative assays should in future be calibrated against the WHO HBV DNA standard[8] to achieve better comparability of the results and aid in the establishment of reliable, clinically relevant thresholds for HBV DNA loads that are yet poorly defined.[9] bDNA technology in the format of the VERSANT HBV 3.0 assay meets most of the clinical demands for HBV DNA quantitation, but is still not sensitive enough to answer all analytical questions in this field; for example, it is not suited to decide whether healthcare workers who are HBV carriers can be allowed to perform exposure-prone procedures under the strict guidelines recently issued by the UK Department of Health (decision threshold: 1000 copies HBV DNA/mL[10]).

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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