Abstract
Buccal cell samples have become common resources as reference samples in short tandem repeat (STR) typing. In this study, 29 buccal cell samples were collected with 4 kinds of collection kits, and whether the samples provided DNA of sufficient quality and quantity for STR typing was examined. DNA was extracted with EZ-1 DNA Investigator kit from three 3 mm-diameter punches of a Buccal DNA Collector and an EasiCollect, or from the 4 mm tip of an Omni Swab. DNA was eluted from FTA Elute by heat using three 3 mm-diameter punches. DNA concentration was quantified with Real-time PCR and STR typing was performed. DNA concentration ranged from 0.29-2.34 ng/μl for Buccal DNA Collector, 0.57-14.3 ng/μl for Omni Swab, 0.26-3.49 ng/μl for EasiCollect, and 0.04-3.90 ng/μl for FTA Elute. Complete STR profiles were obtained from all the samples of the Buccal DNA Collector, the Omni Swab and the EasiCollect, but only from 25 of the 29 samples of the FTA Elute. Storage at 4°C for 3 days, or 5 times repeated freezing and thawing drastically reduced the concentration of the DNA solution obtained from the FTA Elute. We concluded that the Buccal DNA Collector, Omni Swab and EasiCollect are suitable buccal cell collection kits for STR typing; however, the FTA Elute must be used cautiously.
