Polymerase chain reaction concentration, measurement

E. Therapeutic response Efficacy of Infergen therapy was determined by measurement of serum alanine aminotransferase (ALT) concentrations at the end of therapy (24 weeks) and following 24 weeks of observation after the end of treatment of adults with chronic HCV infection. Serum HCV RNA was also assessed using a quantitative reverse transcriptase polymerase chain reaction (RT-PCR). At the end of 24 weeks of treatment, ALT normalization was observed in 39% of patients on Infergen and in 35% of patients on interferon alfa-2b Intron A). Only 17% of patients in each group... 

Eig. 5. Several endpoint detection methods were compared for the detection of immuno-polymerase chain reaction (IPCR) amplificate from a direct IPCR (Fig. 3A) of mouse-IgG. Although all IPCR/DNA-detection combinations were able to improve the detection limit of a comparable enzyme-linked immunosorbent assays (ELISA) of approximately 10 amol IgG in a 30-fL sample volume, several differences were observed in actual detection limit, and the linearity of the concentration/signal ratio dependent on the DNA quantification was applied. Best results were obtained for PCR-ELISA (see also Fig. 6) in combination with fluorescence- or chemiluminescence-generating substrates (b, c). With photometric substrates (d) or gel electrophoresis and subsequent spot densitometry (a), a 10-fold decrease in sensitivity was observed. In addition to the more sigmoid curve in gel electrophoresis, an enhanced overall error of 20% compared to 13% in PCR-ELISA was observed for two independent assays. The simple addition of a double-strand sensitive intercalation marker to the PCR-amplificate and measurement in a fluorescence spectrometer further decreased sensitivity (e) and appears therefore to be unsuited for IPCR amplificate quantification. (Figure modified according to references 37 and 65.)... 

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