Traditionally, large scale genotyping projects have used DNA derived from whole-blood or lymphoblast cell lines. But over the past several years, a number of investigators have begun to use DNA prepared from saliva for genotyping studies, particularly for use in behavioral genetic studies. However, the comparability of DNA from these two sources has not been rigorously analyzed by unbiased sources.
In this communication, we compare the single nucleotide polymorphism genotyping results from DNA derived from whole-blood samples obtained from 474 participants from the Iowa Adoption Studies with that of saliva samples prepared from 555 members of the Strong African–American Families project.
We found that DNA prepared from whole-blood performed significantly better than that prepared from saliva. Genotyping success was significantly associated with the concentration of human DNA in the saliva sample as determined by quantitative PCR, but not with the total amount of DNA as determined by UV spectroscopy.
We conclude that investigators contemplating the choice of source materials of DNA for genotyping studies will need to balance the ease and economy of saliva-based DNA collection methods with the higher yields and rates of genotyping calls associated with DNA prepared from whole-blood.