Scientists generally consider cryopreservation—flash-freezing at extremely low temperatures—the gold standard for preserving DNA in tissues. However, there is an often-overlooked issue: tissues must be thawed before DNA extraction can be performed. This is where the problem arises. Even the briefest thaw can cause DNA-degrading enzymes in the tissue to become activated. But what if those enzymes could be turned off?
Ocean Genome Legacy (OGL) scientists, including our fantastic undergraduate co-ops, wondered if they could turn DNA-degrading enzymes off by thawing tissues in a chemical preservative that quickly penetrates the tissue, knocking out the enzymes before they can damage the DNA. The researchers thawed tissue samples in two different chemical solutions—ethanol or EDTA—and then compared the extracted DNAs to those obtained directly from frozen tissues without chemical treatment. Their analyses revealed that tissues thawed in EDTA yielded significantly higher-quality DNA.
An added benefit of this discovery is that after treatment with EDTA, scientists can handle their previously frozen samples at room temperature, safely and with ease—no more racing to extract DNA before the nucleases destroy it!
This discovery, recently published in the scientific Journal PLOS ONE, is a big deal because it can add value to millions of frozen tissue samples stored in biological collections worldwide, making them more useful for research that can save lives and protect our environment. OGL is excited to make high-quality DNA more accessible with this new method!
Importantly, this paper wouldn’t have been possible without the incredible work of OGL’s undergraduate co-ops—seven of whom are coauthors on the paper. To find out more about these up-and-coming scientists, check out our social media!
Want to contribute to student research? Support OGL co-op students here.