الفهرس 
Diagnostic assays for detection of HCV infection
: MATERIALS AND METHODSOnly 14 pages are availabe for public view
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Abstract
During the last years, non-A, non-Is hepatitis research has progressed
from hepatitis C virus (HCY) cloning to assays for revelation of HCV antibodies
and the subsequent use of the polymerase chain reaction (PCR) to detect the Hey genome. I he situation of HCV is unique in the viral world it’ far as it remains the first virus identified by molecular l-biology. As long as this virus will. remain unseen and unavailable for large in-vitro production by cell culture,
Recombinant proteins, or synthetic fetidness, will be the sole source of viral Components utilizable as antigens for immunological investigations.
Since the identification of the hepatitis C virus, serological assays for., the detection of antibodies HCV have been developed with increasing sensitivity. and specificity from first-generation assays using only antigens encoded by the NS4 region of the genome to scrod generation using antigens from three different regions. NS4 and core), then third-generation assays using tour
different antigenic regions (NS3, NS4, NSS and core). however, the antibody
assays did not discriminate between viraemic patients and patients who have
cleared the virus. anti-HCY antibodies may be not present for 2-6
months in the patients blood during the acute stage of HCY infection since
viraemia precedes die ~’9;Jearanceor’ anti-HCY antibodies. Infection itself has be diagnosed by detection of the virus or its components and HCV viraemia C:’:1 only be diagnosed by HCV RNA detection. For universally applicable detection ”methods of HCY-RNA in plasma or liver tissue, amplification of HCV -specific
nucleic acid is necessary . ”
” In most of the published studies on HCV-viraemia in blood, liver tissue
and-peripheral blood mononuclear cells, , copy DNA-polymerase chain reaction (cDNA-PCR) of HCV RNA is the method of choice for the amplification of virus ;specific nucleic acid. Since HCV is ” RNA virus and DNA is the template for PCR, the viral RNA sequences first have to be reverse transcribed to cDNA.
.subsequently, the cDNA can be amplified by PCR- The PCR method is based on. repetitive cycling of the reaction mixture in three temperature-determined steps.
By repeating these three. steps in an automated incubator, usually 35 times,an immense, theoretically exponential amplification of the region of the target DNA flanked by the primers is achieved