In vast regions of the world where refrigeration is not available, preserving urine and blood samples for testing is virtually impossible. But scientists have developed a way to properly store these samples without refrigeration. Photo by Imgin/Shutterstock

Feb. 28 (UPI) -- Scientists have developed a method for storing blood and urine samples in regions of the world without refrigeration.

Researchers at Washington University in St. Louis found that storing samples in tiny metal-organic hybrid structures could be an alternative to cold storage. Their findings are published in the March issue of the journal Chemistry of Materials.


"Handling, transport and storage of biospecimens such as blood and urine without refrigeration are extremely challenging," the authors write in the paper. "This formidable challenge leads to an inevitable reliance on a 'cold chain' for shipping, handling and storage of biospecimens throughout the world."

They noted that preservatives such as boric acid only work for a short time in storage. And dried blood samples are tough to implement in resource-limited areas, and "can result in aggregation."

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Srikanth Singamaneni and colleagues previously showed that metal-organic frameworks can preserve proteins in biosensors because they have porous structures. So, the team sought to overcome the challenges of sample degradation with MOFs.

In new research, they mixed MOF precursors into blood and urine samples from healthy volunteers, who had been "spiked" with biological markers for ovarian cancer and acute kidney damage. They then air-dried the samples and stored them in temperatures ranging from 77 to 140 degrees Fahrenheit for up to four weeks.

The researchers concluded this technique was as effective at preserving biomarkers as refrigeration.

"Overall, this energy-efficient and environmentally friendly approach will not only alleviate huge financial and environmental burden associated with 'cold chain' facilities, but also extend biomedical research benefits to underserved populations by acquiring reliable clinical samples from regions/populations currently inaccessible," the researchers wrote.