RESUMO
Purpose: Rapid and specific detection of viral nucleic acid is increasingly important in the diagnosis of infectious diseases. The objective was to develop a rapid, efficient process of nucleic acid based detection of hepatitis C virus (HCV) infection for its diagnosis and treatment follow‑up. Materials and Methods: A two‑step nested reverse‑transcriptase polymerase chain reaction (RT‑PCR) has been standardised on a sample set of 125 individuals from different liver clinics in Kolkata. The method utilises a novel fast nested RT‑PCR for HCV detection and genotyping from HCV infected patient plasma with high processivity. Results: The overall time required from ribonucleic acid (RNA) isolation to nested PCR amplified product detection is reduced to 42% when compared with conventional nested RT‑PCR amplification. The method is sensitive as conventional PCR and detected all HCV RNA positive samples. Sequencing, phylogenetic analysis of the PCR amplified product by this method showed concordant genotypes with conventional PCR. Conclusion: Though being a two‑step process, this method is fast, cost‑efficient, reliable and feasible for regular HCV RNA screening and apt even in resource limited settings. This method could be translated to regular nucleic acid screening for other infectious diseases as regular PCR regimen.
RESUMO
Two azoreductases (I and II) were purified to homogeneity from extracts of E. coli K12. Azoreductase I was a dimer of two identical subunits of molecular weight 28000 whereas azoreductase II was a monomer of 12,000 molecular weight. Both NADH and NADPH functioned as electron donors for the azoreductases. Azoreductase I and II used Ponceau SX, Tartrazine, Amaranth and Orange II as substrates. Ponceau SX was the best substrate for both the enzymes. However, azoreductase II utilized tartrazine, amaranth and orange II less efficiently than azoreductase I.