Wajahat Wajeehah, Azad Z R Azaz Ahmad, Nazir Sadaf, Nasir Gazia
Department of Food Technology, Jamia Hamdard, New-Delhi, 110062 India.
Department of Post Harvest Engineering and Technology, Aligarh Muslim University, Aligarh, Uttar Pradesh 202002 India.
J Food Sci Technol. 2022 Apr;59(4):1538-1548. doi: 10.1007/s13197-021-05164-8. Epub 2021 Jun 20.
The study evaluated the use of Real Time-Polymerase Chain Reaction (RT- PCR) to detect the adulteration of camel milk with goat, cow milk. DNA was isolated from camel milk, camel milk powder, camel milk soap, cow milk, and goat milk using DNA extraction kit. RT- PCR amplified a single piece of DNA into millions of copies. The camel specific primers were designed using the primer- 3 online software and quantification of the isolated DNA was carried out by RT- PCR system through DNA standard curves and cycle threshold (Ct) values. The detection limit of DNA template was in the range of 0.001-0.002%. The reaction mixture (20μL) contained 10 μL SYBR Green master mix, 0.3 μL of 10 μM of each primer and 5 μL DNA. Thermal cycling consisted of an initial denaturation at 95 °C for 1 min, followed by 40 cycles for 15 s at 95 °C and 60 °C for 30 s. The primer pairs used were confirmed for their PCR efficiency, and specific products were evaluated by melt curve analysis. Results indicated positive amplification for the camel milk, camel milk powder, and camel milk soap but negative amplification for cow and goat milk. In conclusion, the RT- PCR based identification is a low cost and appropriate method for camel milk and its products. Although, the yield of DNA from camel milk soap after isolation is low but the isolated DNA segment was easily identified.
该研究评估了使用实时聚合酶链反应(RT-PCR)检测骆驼奶中掺有山羊奶和牛奶的情况。使用DNA提取试剂盒从骆驼奶、骆驼奶粉、骆驼奶皂、牛奶和山羊奶中分离DNA。RT-PCR将单段DNA扩增成数百万个拷贝。使用在线软件Primer-3设计骆驼特异性引物,并通过RT-PCR系统利用DNA标准曲线和循环阈值(Ct)值对分离出的DNA进行定量。DNA模板的检测限在0.001%-0.002%范围内。反应混合物(20μL)包含10μL SYBR Green预混液、0.3μL每种10μM的引物和5μL DNA。热循环包括在95°C初始变性1分钟,随后40个循环,95°C 15秒,60°C 30秒。对所使用的引物对的PCR效率进行了确认,并通过熔解曲线分析评估了特异性产物。结果表明骆驼奶、骆驼奶粉和骆驼奶皂呈阳性扩增,而牛奶和山羊奶呈阴性扩增。总之,基于RT-PCR的鉴定方法是一种低成本且适用于骆驼奶及其制品的方法。虽然,分离后骆驼奶皂的DNA产量较低,但分离出的DNA片段易于鉴定。