U.S. Food and Drug Administration, Center for Veterinary Medicine, Office of Research, 8401 Muirkirk Road, Laurel, Maryland 20708, USA.
J Food Prot. 2010 Jun;73(6):1090-6. doi: 10.4315/0362-028x-73.6.1090.
The capability of eight commercially available DNA extraction kits to extract bovine DNA originating in meat and bone meal from fortified feed was evaluated. Four different batches of bovine meat and bone meal (BMBM) were used for DNA extraction with the eight commercial DNA extraction kits. Within each kit, there were minimal differences in the batch-to-batch amounts of extracted DNA. There were differences between the kits in the amounts of DNA that could be extracted from the same amount of starting BMBM. These differences did not translate into differences in the amount of amplifiable DNA from BMBM-fortified dairy feed. Using a validated real-time PCR method, the kit yielding the highest amount extractable DNA was completely unable to yield a positive PCR result; one other kit was also unable to produce a positive PCR result from DNA extracted from BMBM-fortified feed. There was a complete lack of a correlation between the amount of bovine DNA isolated from BMBM by a given extraction kit compared with the relative amounts of DNA isolated from fortified animal feed as evidenced by the cycle threshold values generated using the real-time PCR method. These results demonstrate that extraction of DNA from processed animal protein is different for pure ingredients and fortified animal feeds. These results indicate that a method specifically developed using just animal-derived meat and bone meal may not yield a functional assay when used to detect animal tissues in complete animal feed.
评估了 8 种市售 DNA 提取试剂盒从强化饲料中提取来源于肉骨粉的牛 DNA 的能力。使用 8 种商业 DNA 提取试剂盒从 4 批不同的牛肉骨粉（BMBM）中提取 DNA。在每个试剂盒中，提取的 DNA 批次间量差异极小。从相同量的起始 BMBM 中提取的 DNA 量，不同试剂盒之间存在差异。这些差异并没有转化为 BMBM 强化奶制品饲料中可扩增 DNA 的量的差异。使用经过验证的实时 PCR 方法，提取可提取物 DNA 量最高的试剂盒完全无法产生阳性 PCR 结果；另一个试剂盒也无法从强化饲料中提取的 DNA 产生阳性 PCR 结果。从 BMBM 强化动物饲料中提取的牛 DNA 量与使用实时 PCR 方法生成的循环阈值值所证明的从强化动物饲料中提取的 DNA 的相对量之间完全没有相关性。这些结果表明，从加工动物蛋白中提取 DNA 对于纯成分和强化动物饲料是不同的。这些结果表明，当用于检测完整动物饲料中的动物组织时，仅使用动物源性肉骨粉开发的方法可能无法产生有效的检测。
