New saliva DNA collection method compared to buccal cell collection techniques for epidemiological studies

Abstract

Epidemiological studies may require noninvasive methods for off-site DNA collection. We compared the DNA yield and quality obtained using a whole-saliva collection device (Oragene DNA collection kit) to those from three established noninvasive methods (cytobrush, foam swab, and oral rinse). Each method was tested on 17 adult volunteers from our center, using a random crossover collection design and analyzed using repeated-measures statistics. DNA yield and quality were assessed via gel electrophoresis, spectophotometry, and polymerase chain reaction (PCR) amplification rate. The whole-saliva method provided a significantly greater DNA yield (mean +/- SD = 154.9 +/- 103.05 microg, median = 181.88) than the other methods (oral rinse = 54.74 +/- 41.72 microg, 36.56; swab = 11.44 +/- 7.39 microg, 10.72; cytobrush = 12.66 +/- 6.19, 13.22 microg) (all pairwise P < 0.05). Oral-rinse and whole-saliva samples provided the best DNA quality, whereas cytobrush and swab samples provided poorer quality DNA, as shown by lower OD(260)/OD(280) and OD(260)/OD(230) ratios. We conclude that both a 10-ml oral-rinse sample and 2-ml whole-saliva sample provide sufficient DNA quantity and better quality DNA for genetic epidemiological studies than do the commonly used buccal swab and brush techniques.