Lyophilization Enables Point-of-Care Diagnostics Development

For infectious diseases, time is of the essence. The rapid identification of new infections can help prevent further spread and often improve patient outcomes. However, tools for diagnosing infectious disease typically require bulky machinery, specialized training, and significant capital to maintain, placing them out of reach for many point-of-care facilities and remote communities.

To enable faster, more accessible diagnostics, researchers are turning to the ancient process of lyophilization.

Broadly known as freeze-drying, the process of lyophilization has been a tool for long-term preservation for thousands of years. The process removes liquids from a material using sublimation. Without water, bacteria cannot grow, leaving freeze-dried materials well-preserved and shelf stable.

While broadly applied in food preparation, lyophilization can be equally useful in the preservation of laboratory reagents, and it may ultimately help improve access to infectious disease testing.

The diagnosis of infectious diseases is increasingly done using real-time PCR technology. In such assays, enzymes amplify DNA from the suspected pathogen. Some enzymes and reagents are stable at room temperature, but many are not; these are typically stored in glycerol stocks or as lyophilized powders.

Unless stored at –80°C, the presence of liquid has a detrimental impact on the long-term stability of PCR enzymes. But doing so requires cumbersome, energy-demanding freezers, which can be an obstacle for smaller facilities. In contrast, lyophilized powders can be easily stored at room temperatures or in 4°C refrigerators.

“Without the need for freezers—storage, utilization, and transportation of the material is much, much simpler,” explains Juozas Šiurkus, Ph.D., an expert in lyophilization and Thermo Fisher Scientific’s Lead R&D Manager for Process Development.

For point-of-care diagnostics development, such simplicity is key. However, the enzymes needed for these assays, Šiurkus says, “are the hardest enzymes to lyophilize because they usually lack intramolecular bonds that would help stabilize them, so they’re very flexible.”

Investigators have been researching the properties of enzymes to learn how best to lyophilize them. Some companies have even created a suite of lyophilization-ready enzymes. These enzymes can be used to build freeze-dried mixtures of PCR reagents that enable stable sample-to-answer assays. That can make it considerably easier to bring diagnostics to patients—wherever they are.

Explore: Lyo-ready enzymes
Webinar: Lyophilization—Changing the Game for Molecular Diagnostics