广博世纪

PCR technique has been widely applied into the clinic detection and TaqMan probe quantitative PCR technique has also been the most usual nucleic acid detection technique in the clinic. However, （a）Due to very complicated constituents in the clinic samples, and no perfect extraction methods of clinic nucleic acid up to now, the total nucleic acid extracted from it contain DNA and RNA with all kinds of sequences. (b) The product of PCR reagent kit is usually obtained by optimized experiments according to pure and single sequence DNA, whose specificity is confirmed by three segments of specific nucleic acid sequences including two segments of primers and one probe (aiming at TaqMan probe reagent). (c) when there is deviation of hybridization temperature, the specificity of traditional hybridization technique (Southern、Northern etc.) can not be guaranteed, which lead to presence of nucleic acid hybridization pair with one or two bases mismatch. If the clinic samples present nucleic acid sequences which are isogenous or approximate isogenous with three segments of nucleic acid sequences (mismatch one or two bases) or provided with degenerate energy level the detection results of TaqMan probe quantitative PCR will contain the conditions of non-specific false positive signal or inaccurate quantity (competition of multiple PCR). (d) If the reagent kits are not application for batches checked as quantity control, the activity of specificity of Taq enzyme will be not guaranteed because of transport and storage, and it’s very easy to cause non-specific false positive signals for clinic samples with low concentration (concentration is less than 1000 or 10000 copies, namely Ct is greater than 33). Based on traditional hybridization (or three-dimensional hybridization, XYZ characterize the length of DNA segments, base buildup, and DNA sequence), four-dimensional hybridization technique introduces temperature as the fourth parameter of nucleic acid hybridization technique. It describes the specific characteristics of hybridization results in the four-dimensional temperature space. In the traditional concept, TaqMan probe mode can not do fusion curve analysis. However, by making use of 4-Dimension Hybridization Reaction Reagent Kit, TaqMan probe mode can do it. 4-Dimension Hybridization Reaction Reagent Kit contains special patented constituents, whose detction results are stable, reliable, and better reduplicative, and it helps analyze the characteristics of false positive signals. (Specific or non-specific)