Comparison between DNA obtained from buccal cells of the upper and lower gutter area.

This study compared quantitatively and qualitatively the DNA extracted from buccal cells collected from the upper or lower gutter areas. Buccal cells were collected from the upper (n=15) and lower gutter (n=15) region from 15 volunteers using a special cytobrush (Gentra), totaling 2 collections from each individual. DNA was extracted from the samples according to the manufacturer's instructions. The DNA obtained was qualitatively and quantitatively evaluated by 2 calibrated blind examiners using spectrophotometry and analysis of DNA bands (0.8% agarose gel electrophoresis). Data was statistically analyzed by one-way ANOVA (alpha=0.05). Means and standard derivation (SD) for total DNA yield from the upper and lower gutter area were 12.2 microg (12.0) and 9.4 microg (8.5), respectively (p=0.821). There was higher (p<0.05) DNA purity for the upper gutter (1.79; 0.05) when compared to lower gutter area (1.66; 0.10). Regarding to the DNA quality, no differences were observed between the 2 location sites, but all samples showed similar degree of degradation. In conclusion, it would be recommendable that buccal cells for DNA extraction be collected from the upper gutter area in the attempt to increase DNA purity.