Table 4

Advantages and disadvantages of using treated cards to collect buccal cell DNA

FeatureAdvantagesDisadvantages
CollectionEasy to administerThree-step method (brush, expectorate, transfer) versus one-step for swab/brush only method or rinse method
NoninvasiveAssistance by study personnel required
Limited exposure to blood-borne pathogens
Medically trained personnel not needed
Dries within 1 h
TransportNo liquid sample handlingNone
Compact and lightweight
StorageNo processing requiredDNA yields using standard extraction procedure may decline after 9 mob
Efficienta
High quality DNA obtained after 9 mob
Room temperature and cold storage comparableb
DNA extractionFast and easycDNA extract unpurifiedc
Relatively inexpensiveMore rigorous methods may be required for stored samples (see Storage)
Can process portion and store remainder
DNA yield2.3 μg of human DNA (median)Highly variable (0.2–53.8 μg of human DNA)
Ample for hundreds of PCR assays
May be increased 30–50-fold by whole genome amplification
Brush may contain additional DNA
PCR amplificationHigh success rate (51 of 52; 98.1%)Some samples unsuitable (1 of 52; 1.9%)
Cost of suppliesModest: $4.72/subjectdMore expensive than collecting up to several swabs/brushes
  • a For example, a 27-ft3− 70°C freezer can hold 14,560 cards.

  • b DNA yields and suitability for PCR evaluated after storage at room temperature, −20°C, and −70°C for 9 months.

  • c The manufacturer’s suggested extraction protocol is a fast and simple method producing a crude DNA extract; more extensive methods that include purification may be preferred.

  • d Includes card ($3.90), brush ($0.47), sterile cup ($0.26), and transfer pipette ($0.09).