Figure 4.

Comparison of SNP genotyping accuracy using DNA isolated from saliva, buccal swab and blood samples. 100 ng of canine genomic DNA isolated using the Oragene ^®•ANIMAL kit (An), buccal swabs (Bu) or blood (Bl) were used for SNP genotyping by PCR-RFLP. A 135-bp fragment encompassing the SNP was amplified by PCR from the paired samples from 15 dogs. PCR reactions were subsequently digested with EcoRI to discriminate between the two alleles (C/T). The genotype of each animal is inferred from the pattern and size of DNA fragments obtained after digesting with EcoRI, resolving the reactions by agarose gel electrophoresis and staining with SYBR ^® Green. Presence of the 83-bp and 52-bp restriction fragments is consistent with the C allele, whereas presence of the 135-bp undigested fragment is consistent with the presence of the T allele. Odd-numbered lanes contain undigested PCR product, and even-numbered lanes contain PCR product digested with EcoRI. The genotype of each dog is also indicated.