Saliva vs. Blood for DNA Genetic Analysis 

In this article, we explore the use of saliva vs blood for DNA Genetic Analysis. 

Feature	Saliva	Blood
Invasiveness	Non-invasive; easy, self-collection	Invasive; requires trained personnel,  needles
DNA Yield	Lower yield	Higher yield
DNA Purity	Comparable purity to blood	Comparable purity to saliva
Genotyping   Accuracy	High concordance (>97%); slightly lower call rates on  some platforms	High concordance (>97%); higher call  rates
Contamination Risk	More prone to contamination (bacteria, food)	Less prone to contamination
Suitability	Adequate for most genetic tests; not all complex/rare  marker tests	Suitable for all types of genetic tests
Convenience	Can be collected at home; higher compliance	Requires clinic visit; lower   compliance
Cost	Lower total cost; no need for phlebotomist	Higher cost; requires trained staff
Storage/Transport	Stable at room temperature; easy shipping	Needs cold chain for long-term   storage

 

Key Points 

• Accuracy and Quality: For most genetic analyses, saliva and blood yield highly concordant results,  with minimal differences in DNA quality and genotyping accuracy. However, blood samples tend to  have higher genotyping call rates and more amplifiable human DNA. 
• DNA Yield: Blood provides significantly more DNA per sample than saliva (up to 10x more), but  saliva usually yields enough DNA for standard genotyping and sequencing needs.
• Contamination: Saliva samples are more susceptible to contamination from bacteria and food,  which can affect certain tests.  
• Convenience and Compliance: Saliva collection is non-invasive, can be done at home, and leads to  much higher donor compliance rates. Blood draws require trained personnel and are less  convenient. 
• Cost and Logistics: Saliva collection is less costly overall, especially when considering the need for  phlebotomists, clinic visits, and cold-chain storage for blood. 
• Suitability: While saliva is suitable for most genetic tests, some complex or rare marker analyses  may still require blood due to higher DNA yield and purity. 

Summary 

Both saliva and blood are reliable sources for DNA genetic analysis. Blood provides higher DNA yield and  slightly better genotyping performance, but saliva offers comparable accuracy for most purposes, with  major advantages in convenience, compliance, and cost-effectiveness. Saliva is especially advantageous for  large-scale studies, remote sampling, and situations where non-invasiveness is critical.  

Have questions about your DNA or RNA extraction projects? Talk to AutoGen. We’re  always happy to help you make the best decisions for your project needs.