can you find your genetic make-up using remote blood sampling?
by Neoteryx | 3 min read
A drop or two of blood can reveal a person's genetic make-up and their unique biomarkers. These are clues that can indicate where a person's ancestors came from, and also whether or not a therapeutic drug or other medical intervention will be effective for that individual. Because blood contains insightful information about genetics, health, and the body's response to diseases or the drugs that treat them, it is critical to collect blood samples from study participants for clinical trials and public health studies.
Collecting blood samples from study participants has been key to whole-genome sequencing and studies that increase our understanding of biomarkers, but traditional blood collection procedures have not always been patient-friendly or convenient. Traditional blood draws are invasive and require visits to the clinic or lab. This poses a barrier to finding people who are willing to participate in clinical studies. Such studies would benefit from less invasive or more convenient blood collection methods, which would enable them to recruit larger and more diverse groups of study subjects.
Saliva DNA Extraction
A less invasive approach to sampling is saliva-derived genomic DNA, which is considered user-friendly, cost-effective, and painless. This approach can often be done remotely, which makes it more attractive to study participants. In fact, many companies provide home specimen collection kits that include supplies to self-collect saliva samples for DNA testing (Oragene, 23andMe, Ancestry.com, etc.).
However, saliva sampling may not work for every type of study. While saliva is considered a reliable source for DNA genotyping, research shows that it produces much lower genotyping call rates than blood samples.
A study to determine the quality of saliva for whole-genome sequencing in cardiac patients found saliva samples failed the quality control requirements by a more considerable margin than blood samples. The researchers stored the saliva samples at -200°C before genotyping, but they still had a low DNA yield.
The main reason for the low DNA yield was high DNA fragmentation and protein contamination in saliva. Also, there’s concern that saliva may contain large proportions of DNA from oral bacteria and food, which could interfere with the accuracy of the test results.
Blood DNA Extraction
A study to determine the quality of whole-genome sequencing from blood samples found that out of 531 blood samples that were collected, only 6% failed the quality control requirements, compared to a 46% failure of saliva samples. This indicates that blood samples are more reliable for both direct sequence analysis and high-resolution curve melting analysis of DNA.
Remote Blood Sampling for Genetic Studies
There are remote, minimally invasive blood sampling methods available, such as DBS (dried blood sampling) and VAMS (volumetric absorptive microsampling), which can provide high-quality samples that furnish accurate DNA results. These methods are viable alternatives to traditional whole blood sample collection for DNA sequence analysis.
Why Dried Blood for DNA Blood Sample Collection?
Dried blood sampling involves the collection of blood using remote collection devices like the Mitra® Microsampler. An improvement over dried blood spot cards, the Mitra device uses VAMS technology to collect precise samples as small as 10 µl for dried blood lab analysis. It eliminates the need for larger quantity blood draws using venous blood collection methods and tubes of blood.
Surprisingly, the use of small dried blood samples doesn’t limit the amount of data that can be gathered. On the contrary, dried blood samples allow lab researchers to perform many tests to gather big data, including genetic fetal screenings, DNA testing, drug testing, and infectious disease analysis.
How Remote Blood Sampling Works
There are home health kits available, such as the Mitra® Blood Collection Kit, that make it easy for people to collect their own blood samples remotely, and mail them directly to the lab for genetic testing or health screening.
The remote blood sample collection process is straightforward, involving a few simple steps:
- Once the at-home blood sample collection kit arrives, unwrap the device and supplies; and use the enclosed lancet to prick the end of your finger.
- Use the device to collect a drop or two of blood from your fingertip.
- Close the device in its protective cartridge.
- Seal the cartridge in the enclosed packaging and mailing envelope.
- Mail it to the lab.
Once the Mitra blood sample reaches the lab, it’s processed as a dried blood sample. Dried Mitra samples remain stable for a few weeks at ambient temperatures, with no cold storage required.
Remote Dried Blood Sampling vs. Saliva Sampling for Genome Sequencing
While both methods provide reliable sources for whole-genome sequencing, dried blood sampling remains a better sample collection method. With the invention of remote and non-invasive blood collection devices like the Mitra device and Mitra Blood Collection Kit, many researchers now prefer using remote blood samples for whole-genome sequencing. For whole-genome sequencing, the microsampling experts at Neoteryx, makers of the Mitra with VAMS technology, recommend sampling a minimum of 30 uL.
Another benefit of dried blood sampling is that DNA has more longevity in dried blood. Studies show that DNA remains intact in dried blood samples for many months after collection.