Saliva as an alternative source of high yield canine genomic DNA for genotyping studies

The domestic dog presents an attractive model system for the study of the genetic basis of disease. The development of resources such as the canine genome sequence and SNP genotyping platforms has allowed for the implementation of canine genetic studies. Successful implementation of such studies depends not only on the quality of individual DNA samples, but also on the number of samples obtained. The latter can be maximized using a non-invasive DNA collection method that can increase study participation. We compared the DNA yield and quality obtained from blood and buccal swabs to those obtained using a non-invasive saliva collection kit (Oragene *ANIMAL kit). We also assessed the success rate of PCR amplification and genotyping accuracy of DNA isolated using these collection methods.

Comparison of DNA yields from matched saliva, blood and buccal swab samples showed that yields from saliva were significantly higher than those from blood (p = 0.0198) or buccal swabs (p = 0.0008). Electrophoretic analysis revealed that blood and saliva produced higher quality DNA than buccal swabs. In addition, a 1.1-kb PCR fragment was successfully amplified using the paired DNA samples and genotyping by PCR-RFLP yielded identical results.

We demonstrate that DNA yields from canine saliva are higher than those from blood or buccal swabs. The quality of DNA extracted from saliva is sufficient for successful amplification of a 1.1-kb fragment and for accurate SNP genotyping by PCR-RFLP. We conclude that saliva presents a non-invasive alternative source of high quantities of canine genomic DNA suitable for genotyping studies.