The protection and stabilization of whole blood at room temperature

Preservation of biospecimens for biobanking applications traditionally involves freezing while maintaining the integrity of the product throughout multiple freeze-thaw cycles. The protection and stabilization of DNA at room temperature (RT) may eliminate the costs associated with freezer storage and reduce the maintenance costs for biobanks. However, there is a paucity of information describing the yield, purity, and integrity of DNA extracted from biospecimens stored at RT. To evaluate the yield, purity, and integrity of DNA extracted from whole blood samples stored at RT (18°C), low (-20°C), and ultra-low (-80°C) temperatures, whole blood samples from sheep and human subjects were collected, and aliquots were stored at RT (18°C), -20°C, and -80°C. Blood samples at RT were stored utilizing biostabilization technology designed to protect genomic DNA in whole blood. The quantification of the extracted DNA was determined by spectrophotometry, and the integrity was assessed following gel electrophoresis. Storage temperature did not influence the DNA yield (p=0.52); DNA yield averaged 13.6 ± 1.2 ng/μL across all storage temperatures. However, DNA yield was influenced (p=0.04) by species. The DNA yield was not influenced by a species × storage temperature interaction (p=0.84). Among the samples stored at RT, the species, type of technology utilized, and the interaction did not influence (p>0.13) DNA yield for both DNAgard and DNAstable. The 260/280 ratio was influenced by a species × storage temperature interaction (p=0.01). Generally, the 260/280 ratios were higher (p<0.05) for human samples stored at low and ultra-low temperatures compared to sheep samples stored at similar temperatures. Ambient temperature-based technologies offer an alternative to low temperature biospecimen preservation for blood that can be utilized by biobanks to reduce freezer storage costs while maintaining the quality of the biospecimen.