RNA sequencing (RNA-Seq) has become an invaluable tool for research and diagnostics, helping scientists explore gene expression, identify disease markers, and develop new therapies. However, one of the challenges when working with RNA is its instability—it can easily degrade, which can compromise the results of experiments. To ensure high-quality RNA for analysis, proper storage and extraction methods are critical, especially when dealing with blood samples.

Now, researchers at the University of Malta have developed a method to successfully isolate high-quality RNA from blood samples that had been stored for an extended period—10 years, in fact. The research focused on blood samples collected in two common anticoagulants: EDTA and citrate. The blood samples were stored at -85°C in Boom’s lysis buffer, a common storage solution that helps preserve RNA integrity over time.

The researchers used a modified protocol based on the Zymo Research Quick-RNA kit to extract the RNA. This method was compared to the original Boom method, and the results showed significant improvement in RNA quality. The isolated RNA maintained its integrity over the 10-year storage period, making it suitable for RNA sequencing (RNA-Seq) analyses.

Summary of the modified protocol of the Zymo Research Quick-RNA Whole Blood kit

What’s particularly promising is that the RNA sequencing data obtained from these long-stored blood samples was of high quality—comparable to data from blood samples that had been freshly frozen using RNA stabilizing tubes. The study also found that there was a strong correlation between RNA extracted from blood stored with either EDTA or citrate, showing that both anticoagulants are effective for preserving RNA.

This research highlights a significant breakthrough in RNA preservation and isolation. By demonstrating that RNA can be successfully extracted from blood samples stored long-term at extremely low temperatures, this study opens the door to more affordable and accessible biobanking methods. Researchers and clinicians can now collect smaller blood samples, store them for longer periods, and still obtain high-quality RNA for detailed gene expression analysis. This advancement makes RNA-based diagnostics and research more feasible, even for large sample collections, while ensuring that RNA remains intact for accurate analysis.