Did you know that over 75% of DNA testing companies use buccal swabs as their primary sample collection method? This non-invasive method, using cheek cell collection, has gained popularity for its simplicity, especially in easy at-home tests.

However, in contrast, blood samples—though more invasive—are often the go-to in clinical settings due to their higher DNA yield and reliability. 

While buccal swabs are ideal for non-invasive testing, blood samples offer more comprehensive genetic data, making them the preferred choice for more detailed analyses. The key to choosing the best option lies in understanding what your specific test requires.

What is a Buccal Swab?

A buccal swab is a straightforward process for collecting a DNA sample by swabbing the inner surface of the cheek. A sterile cotton or foam swab is gently rubbed along the inside of the cheek to collect epithelial cells, which contain DNA. 

This method is very convenient since it doesn’t require needles or special equipment. Its simplicity and comfort make it a popular choice for at-home genetic tests. To collect enough cells, you need to swab firmly but gently. Once the sample is collected, let the swab air dry before sending it to the lab for analysis.

For a detailed guide on performing this method at home, check out our article on collecting a DNA sample using a buccal swab.

Typical uses of buccal swabs in genetic testing:

  • Paternity and ancestry testing
  • Forensic DNA analysis
  • Pharmacogenetic testing
  • Immigration-related DNA verification

Pros

  • It is less invasive than a blood sample.
  • Requires minimal effort and training.
  • Ideal for simple setups.
  • Child-friendly and less painful

Buccal swabs are ideal for large-scale genetic studies and population screenings because they’re easy to collect, and people are more likely to comply. The process requires very little equipment, making it easier to involve many participants and minimize logistical issues.

Cons

  • Buccal swabs often produce less DNA compared to blood samples.
  • DNA yield can vary based on technique and individual factors.
  • More samples may be needed for reliable results.
  • Prone to contamination from food, drink, or bacteria, which can degrade DNA.
  • Improper handling or storage in warm or humid environments increases the risk of DNA degradation.

To mitigate these issues, buccal swabs should be stored in a cool, dry place and processed promptly.

Visit our page on collecting a saliva sample for genetic testing to learn more about how saliva samples are collected and what precautions to take.

What is a Blood Sample for Genetic Testing?

A blood sample for genetic testing is one of the most common ways to analyze a person’s DNA and understand their genetic makeup. It usually involves drawing blood through a simple needle insertion into a vein. 

The sample can be whole blood, serum (the liquid left after the blood clots), or plasma (the fluid containing clotting factors). Whole blood is rich in white blood cells, which hold the DNA needed for genetic testing. After collection, the blood is labeled and processed, often using a centrifuge to separate the serum or plasma.

Clinicians have historically preferred blood-based samples for genetic testing because of their reliability and the high quantity of DNA they provide. Blood samples remain essential in diagnosing genetic disorders, and clinicians commonly use them when comprehensive genetic data is needed.

Pros

  • Provides a higher yield of DNA
  • Less likely to be contaminated
  • Provides a more comprehensive genetic profile

Clinicians often recommend blood samples for genetic testing because the established protocols ensure consistent and accurate results. Medical settings standardize the collection process, and blood provides high-quality DNA, making it the preferred method for genetic diagnostics. It’s a trusted approach as it reduces the risk of contamination and provides enough material for comprehensive testing.

Cons

  • Venipuncture can be uncomfortable.
  • More expensive than non-invasive methods.
  • Blood samples must be collected by a professional in a laboratory setting, making them less convenient than at-home collection methods.
  • Blood samples degrade quickly if not stored properly. 

Blood collection involves using a needle, which can sometimes cause discomfort, bruising, or even light-headedness for some people. There’s also a tiny chance of infection or fainting, especially for those with needle phobias or certain medical conditions.

Buccal Swab vs Blood Sample: Comparative Analysis

Both buccal swabs and blood samples are strong for DNA sampling. Buccal swabs are non-invasive and ideal for those uncomfortable with needles. In contrast, blood samples provide more DNA and detailed genetic information, making them better for clinical tests.

If you’re exploring the differences between sample types, knowing how they impact your test results is essential. To better understand how blood and saliva samples compare in genetic testing, look at our in-depth guide. This resource covers everything you need to know to make an informed choice for your genetic testing needs.

Purpose

Buccal swabs vs blood samples in genetic testing: 

  • Buccal Swab: This is best for non-invasive tests, like ancestry and forensic analysis. It’s often used in paternity testing and is efficient for large-scale screenings or self-collection.
  • Blood Sample: People prefer blood samples for more detailed genetic tests. They’re ideal for tests that require a high DNA yield, such as prenatal screenings and diagnosing complex disorders.

DNA Yield and Quality

Blood samples provide more DNA than buccal swabs because they contain more nucleated cells. This higher DNA content makes blood samples ideal for tests that require large amounts of high-quality DNA, such as whole-genome sequencing. Buccal swabs, while effective, tend to produce lower DNA yields and may require amplification (a process that increases the amount of DNA to make testing more accessible) for specific genetic tests.

Accuracy

Both buccal swabs and blood samples are reliable options for genetic testing, with accuracy depending on the sample quality and the type of test. Buccal swabs are famous for non-invasive testing and give accurate results when collected correctly. Blood samples, however, are more commonly used in clinical settings because they are less prone to contamination and tend to provide more consistent results.

User Experience and Convenience

Buccal swabs are easier to use than blood samples. They offer a simple, painless way to collect DNA. In contrast, blood samples involve needles, which can cause discomfort. Buccal swabs can also be self-administered, making the process even easier. On the other hand, blood collection usually requires a professional.

Cost and Accessibility

Buccal swabs are more affordable since they don’t need special equipment and can be used at home (typically around $10 to USD 50 per test). This affordability makes them more accessible, especially in low-income areas or for large-scale testing. Blood samples are more expensive because they need professional collection and proper storage (costs can range from $100 to USD 300 per test).

Which One Should You Choose?

When choosing between a buccal swab and a blood sample for genetic testing, you must consider the specific requirements of the test.  Buccal swabs are great for non-invasive testing, while blood samples are better for more detailed genetic analysis.

Choosing Buccal Swab

  • Suitable for children and adults who are needle-averse
  • Easy to handle and can be collected at home
  • Perfect for  general paternity or ancestry testing
  • Ideal for large-scale or population screenings
  • It is ideal when specialized equipment is limited

Choosing Blood Sample

  • Recommended for certain genetic disorders requiring high DNA yield
  • Required when more comprehensive data is needed for detailed clinical tests
  • Often necessary to analyze prenatal DNA or measure complex genetic variants​

Key Takeaways

  • Buccal swabs are simple and non-invasive. They are perfect for paternity, ancestry tests, and large-scale screenings.
  • Blood samples give more DNA and detailed genetic data, often used for clinical tests and diagnosing genetic disorders.
  • Buccal swabs cost less and are easier to use at home, while blood samples cost more because professionals must collect them.
  • The choice between buccal swabs and blood samples depends on the type of test and the amount of DNA quality required.

Frequently Asked Questions

Is Blood Collection Necessary for Certain Genetic Tests?

Blood samples are necessary for specific genetic tests that demand a higher amount and better quality of DNA. They are significant for tests like non-invasive prenatal screening, whole-genome sequencing for inherited conditions, and metabolic disorder testing, where precision and stable DNA are key.

Are Blood DNA Tests More Accurate Than Buccal Swabs?

No, blood DNA tests are not more accurate than buccal swabs. Both methods offer reliable results, with accuracy depending on the sample’s quality and the test type.

How Do I Avoid Contaminating a Buccal Swab Sample?

To prevent a buccal swab sample from becoming contaminated, let it air dry before packaging it. Also, avoid eating, drinking, or smoking for 30 minutes beforehand. Avoid touching the tip of the swab or letting it touch any surfaces before putting it in the collection envelope.