Comparative Study of Buccal Cells Collection Protocols for DNA Extraction

Methods: The different buccal cells collection protocols were assessed and compared for DNA extraction assay by geneMAG-DNA/saliva Collection Kit (Chemicell, Germany). First protocol is saliva collection method with passive drool technique. Second protocol is whish collection method using normal saline, and third protocol is buccal swab method. The experiments were carried out in triplicates. The washed pellets from different protocols were suspended in TE buffer and analyzed for the quality and purity of DNA content by using the NanoDrop Spectrophotometer. The purity of extracted DNA then checked with wavelength of 260 and 280 nm. A ratio of A260/A280 was calculated. The presence of extracted DNA was then confirmed by electrophoresing process, the DNA bands were scanned by Typhoon 9410 variable imager.

Results: In this study, the yield and quality of extracted DNA of buccal cells by using the saliva, swish and buccal swabs collection methods were compared. There was no statistically significance different in higher yield from the swish collection compared with the buccal swab collection method (26.7 µg/µl versus 22.4 µg/µl, respectively; P = 0.133). However in DNA purity checking, there was a significant difference in the swish collection compared with the saliva collection method (1.94 O.D versus 2.09 O.D respectively; P = 0.0208). Moreover, the DNA bands that stained in electrophoresis gel demonstrated clearer and stronger bands in the swish collection method compared with another two methods.

Conclusion: The results obtained demonstrated that the swish collection method showed the better yields and higher purity of extracted DNA of buccal cells. Thus, the swish collection method will be applied in sample collection for down-stream DNA identification application in our study.