• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services

Scientific Publications by FDA Staff

  • Print
  • Share
  • E-mail

Search Publications



Starting Date

Ending Date

Order by

Entry Details

Food Microbiol 2013 May;34(1):100-5

Comparison of six commercial DNA extraction kits for detection of Brucella neotomae in Mexican and Central American-style cheese and other milk products.

Lusk TS, Strain E, Kase JA


Raw or inadequately pasteurized milk from infected animals and cheese made with such milk are a frequent vehicle for human brucellosis infection. Also, biological terrorism is a concern with certain Brucella spp. Due to matrix-associated real-time polymerase chain reaction (qPCR) inhibitors, robust sample preparations are crucial. We compared six commercial nucleic acid extraction kits using nine Mexican and Central American-style soft cheeses or creams and three liquid milk products inoculated with Brucella neotomae, a surrogate for pathogenic Brucella spp. Kits were evaluated by purity and quantity of DNA as determined by qPCR Ct values, reproducibility across cheese and milk types, and cost. At 10(7) CFU/g in four different cheeses, Qiagen statistically outperformed all other kits. When two cheese styles were inoculated at dual levels, Qiagen and High Pure kit extracted samples at 1.5 x 10(5) CFU/g produced average Ct values of 34-39, while PrepSEQ and MagMAX kit extracted samples exhibited higher or no Ct values. High Pure and Qiagen kits excelled also with liquid milk products. Considering matrices, inoculation levels, and kits evaluated, High Pure and Qiagen products produced Brucella DNA of high quality and quantity indicated by the lowest Ct values and were the least expensive.

Category: Journal Article
PubMed ID: #23498184 DOI: 10.1016/j.fm.2012.11.007
Includes FDA Authors from Scientific Area(s): Food
Entry Created: 2013-03-19 Entry Last Modified: 2013-08-31