What is a cheek swab used for?

Uses of Cheek (Buccal) Swabs in Clinical and Research Settings

Buccal swabs are primarily used for collecting DNA samples for genetic testing and for sampling the oral microbiome, offering a non-invasive alternative to blood collection that can be easily performed in various settings.

Primary Applications of Buccal Swabs

1. Genetic Testing

• DNA Collection: Buccal swabs provide sufficient DNA for various genetic analyses 1, 2
  • Yield approximately 1.94-2.44 μg of DNA per swab 1
  • Suitable for high-throughput single nucleotide polymorphism (SNP) analysis
  • Can be used for mutation screening in patients with genetic disorders 3

2. Oral Microbiome Analysis

• Microbial Sampling: Represents a specific intra-oral niche 4
  • Allows collection of bacteria from the buccal mucosa
  • Used in oral microbiome research studies
  • Can be included in multi-site oral sampling protocols

3. Practical Advantages

• Non-invasive collection: More acceptable to patients than blood draws 5
  • Particularly valuable for:
    • Elderly patients
    • Children
    • Population-based studies
    • Remote collection via mail
  • Increases study participation and compliance 2

Technical Considerations

Collection Procedure

• Relatively easy to sample 4
• Can be self-collected by patients or collected by healthcare providers
• Repeated sampling is possible

Sample Quality Factors

• Limitations:
  • Low bacterial diversity compared to other oral sites 4
  • High human DNA proportion relative to bacterial DNA 4
  • Potential contamination from teeth surfaces and saliva 4
  • DNA quality may be affected by degradation 2

Processing Considerations

• Fresh processing yields better results (96.1% success) than mailed samples (77.6%) 6
• DNA from buccal swabs is stable for several years 5
• Failed samples may benefit from additional purification steps 6

Clinical Applications

Genetic Disorder Diagnosis

• Used for mutation screening in suspected inherited disorders 3
  • Example: Corneal dystrophies through TGFBI gene screening
  • Can confirm or refute diagnoses based on clinical features

Infectious Disease Testing

• Should be labeled with specific anatomic source (e.g., "buccal mucosa" not just "mouth") 4
• Multiple swabs may be collected for different tests (culture, microscopy, molecular testing) 4

Best Practices

• Use appropriate collection devices (e.g., Catch-All swabs show good performance) 1
• Follow standardized collection protocols to maximize DNA yield
• Consider immediate processing when possible for optimal results
• Check DNA quality before proceeding to expensive testing procedures 2

Buccal swabs represent a practical balance between ease of collection and sample quality, making them particularly valuable when blood collection is impractical or when specifically studying the oral microbiome.