Nucleic Acid Sample Preparation from Dairy Products and Milk

Abstract

The isolation of RNA and DNA of sufficient quantity, of an optimal intact length (quality), and without contaminants (purity) is important for a range of research initiatives including pathogen detection during an outbreak and the study of the background microflora in dairy products. Nucleic acid isolation is a multistep procedure that may begin with the separation of cells from the matrix, followed by cell lysis, then nucleic acid extraction and recovery. Herein we compare and evaluate published methods used to extract nucleic acids from various dairy matrices. Specific topics include removal of matrix components by centrifugation, organic solvents, and Proteinase K treatment along with cell lysis accomplished by enzymatic (e.g., lysozyme), physical (e.g., freeze/thawing, boiling, bead-beating), and chemical (e.g., detergent) means. Also mentioned is the recent use of automated nucleic acid extraction procedures.