Wolf C, Lüthy J
Laboratory of Food Chemistry, Department of Chemistry and Biochemistry, University of Berne, Freiestrasse 3, CH-3012 Berne, Switzerland.
Meat Sci. 2001 Feb;57(2):161-8. doi: 10.1016/s0309-1740(00)00088-7.
Many meat products nowadays may contain several species in different proportions. To protect consumers from fraud and misdeclarations, not only a qualitative but also a quantitative monitoring of ingredients of complex food products is necessary. DNA based techniques like the polymerase chain reaction (PCR) are widely used for identification of species but no answer to the proportional amount of a certain species could be given using current techniques. In this study we report the development and evaluation of a quantitative competitive polymerase chain reaction (QC-PCR) for detection and quantification of porcine DNA using a new porcine specific PCR system based on the growth hormone gene of sus scrofa. A DNA competitor differing by 30 bp in length from the porcine target sequence was constructed and used for PCR together with the target DNA. Specificity of the new primers was evaluated with DNA from cattle, sheep, chicken and turkey. The competitor concentration was adjusted to porcine DNA contents of 2 or 20% by coamplification of mixtures containing porcine and corresponding amounts of bovine DNA in defined ratios.
如今许多肉制品可能含有不同比例的多种物种。为保护消费者免受欺诈和错误申报之害，不仅需要对复杂食品的成分进行定性监测，还需要进行定量监测。基于DNA的技术，如聚合酶链反应（PCR），被广泛用于物种鉴定，但使用现有技术无法确定某一物种的比例。在本研究中，我们报告了一种定量竞争性聚合酶链反应（QC-PCR）的开发和评估，该方法基于猪的生长激素基因，利用一种新的猪特异性PCR系统来检测和定量猪DNA。构建了一种与猪靶序列长度相差30 bp的DNA竞争物，并与靶DNA一起用于PCR。用来自牛、羊、鸡和火鸡的DNA评估了新引物的特异性。通过以确定比例共同扩增含有猪DNA和相应量牛DNA的混合物，将竞争物浓度调整为猪DNA含量的2%或20%。
