A simple method for the isolation of genomic DNA from mouse tail free of real-time PCR inhibitors

Although real-time PCR is a rapid, quantitative method for the analysis of gene and RNA levels, the presence of inhibitors in samples is an obstacle to its successful use. We have found that genomic DNA isolated from mouse tail tips using a standard proteinase K digestion method caused marked inhibition of real-time PCR. Inhibition was specific for mouse tail DNA since genomic DNA isolated from other tissue sources using the same methodology was readily amplified. We have therefore developed a nonproteinase K DNA isolation method involving the use of Chelex 100 resin. This method produces mouse tail DNA that is free of real-time PCR inhibitors.