Dive into the DNA sequence, and you'll unravel tales of ancestry, insights into health predispositions, and even gauge how the body might react to specific medical interventions. The source of this treasure trove of genetic information? Just a few drops of blood. As we continue to understand our body's genetics, the methods of collecting these invaluable samples are evolving. Let’s explore the age-old debate: blood vs. saliva for genomic sequencing.
Blood Sampling: Why It’s the Gold Standard for Genomic Studies
Collecting venipuncture 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. The traditional methods of collecting blood samples, involving invasive procedures and clinic visits, often deter potential participants. The need for less invasive and more convenient methods becomes glaringly evident.
Saliva DNA Extraction: A Less Invasive Option?
Saliva-derived genomic DNA presents itself as a user-friendly, cost-effective, and painless alternative. The ability to remotely collect saliva, combined with home collection kits from companies like Oragene, 23andMe, and Ancestry.com, makes it an attractive proposition.
But it's not all smooth sailing. While saliva is indeed a reliable source for DNA genotyping, it has its pitfalls. A study on cardiac patients revealed that saliva samples failed quality control requirements by a significant margin compared to blood samples, primarily due to high DNA fragmentation and protein contamination. Add to that the potential contamination from oral bacteria and food residues, and the accuracy of results can be compromised.
Blood DNA Extraction: The More Reliable Choice
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.
The Future: Remote Blood Sampling
Modern innovations, such as dried blood sampling (DBS) and volumetric absorptive microsampling (VAMS), have made remote blood sample collection a reality. Devices like the Mitra® Microsampler, which employs VAMS technology, have revolutionized blood sampling.
Despite their compact nature, dried blood samples, even as small as 10 µl, can be used for a plethora of tests ranging from DNA testing and genetic fetal screenings to drug tests and infectious disease analysis.
How It Works: A Step-by-step Guide to Remote Blood Sampling
The magic happens in the lab where the dried blood sample, which remains stable for weeks at room temperature, gets processed.
Making the Choice: Remote Blood Sampling vs. Saliva Sampling
While saliva sampling offers convenience, dried blood samples present a superior method for genomic sequencing, especially when collected through advanced devices like the Mitra. Experts at Neoteryx, the creators of the Mitra with VAMS technology, recommend a minimum of 30 uL for whole-genome sequencing. Plus, DNA in dried blood exhibits impressive longevity, remaining intact for several months post-collection.
In the quest to decipher our genetic code, while both methods hold their ground, dried blood sampling stands a step ahead, especially with advancements in remote blood collection technology.