EZ1 DNA Buccal Swab Card

QIAGEN's protocol card is designed for use with the BioRobot EZ1 workstation in combination with the EZ1 DNA Tissue Kit for fully automated isolation of total (genomic and mitochondrial) DNA from buccal cells. The magnetic-particle technology yields DNA well suited to genotyping, epidemiological studies, and forensic analyses, and is appropriate for direct use in downstream applications such as amplification and other enzymatic reactions.

Buccal cells are collected by scraping a plastic swab with cotton or Dacron tip, or a nylon cytology brush, against the inside of each cheek 6 times, then air-drying the swab or brush for at least 2 h; the donor should not have consumed any food or drink for 30 min prior to collection. Samples may be processed on the day of collection or stored; storage at –20°C is recommended, although DNA of suitable quality for single-copy gene amplification has been documented from swabs stored at room temperature for 24 months. Table 2 of the supplementary protocol (MA06 Mar-03) reports typical DNA yields for fresh buccal cell swabs (n = 18), 24-month-old buccal cell swabs (n = 6), and 24-month-old buccal cell brush samples (n = 15), all air-dried and stored at room temperature.

For processing, the swab or brush tip is cut or broken into a 2 ml sample tube containing 290 µl of diluted Buffer G2 plus 10 µl Proteinase K, vortexed for 10 s, and incubated at 56°C for 15 min; when processing brush samples the tube is centrifuged briefly at 10,000 x g for 30 s to force the brush to the bottom of the tube. After incubation and a brief centrifugation to collect drops from the lid, the swab or brush is removed from the tube (pressed against the wall with forceps to recover maximum volume), yielding approximately 200 µl of digested sample. Buffer G2 should be diluted in distilled water (1 volume to 0.5 volumes) before use for n+1 samples; use of diluted Buffer G2 does not influence DNA yield or quality. The card is inserted fully into the EZ1 Card slot of the BioRobot EZ1 and the worktable is loaded with reagent cartridges (inverted and tapped), opened elution tubes, filter-tip holders, and opened sample tubes; the automated purification protocol runs for 15–20 min and elutes the DNA in 100 µl. Purified DNA may be stored at 2–8°C for 24 h or at –20°C for longer periods. The product is intended as a general-purpose device, and users are responsible for validating its performance for any particular use; it may be used in clinical diagnostic laboratory systems after the laboratory has validated its complete system as required by CLIA '88 regulations in the U.S. or equivalents in other countries.