Image created by Dr. Michael J. Miller
A new diagnostic method enables the detection of hepatitis C and Zika virus directly from dried whole blood, potentially bringing faster testing to locations where conventional laboratory diagnostics are difficult to access. In a study published in Science Advances, the new approach could overcome a major barrier to accessibility by eliminating the need for complex sample preparation steps.
“In many parts of the world, delayed diagnosis undermines the impact of effective treatments,” said Rashid Bashir, PhD, professor of bioengineering at the University of Illinois Urbana-Champaign. “Despite substantial advancements of molecular diagnostics, clinical outcomes are often not improved because test results arrive after the critical window for intervention has passed, rendering the diagnosis too late to matter. This failure highlights a global need for diagnostics that are not only accurate but also rapid, accessible, and deployable.”
The need is particularly urgent for hepatitis C virus, which can be cured in more than 95% of cases when antivirals are administered in time. However, only about 20% of infected people in high-income countries are diagnosed, and just seven percent receive treatment. In low-income regions, which account for nearly 80% of global hepatitis C infections, fewer than one percent of people are diagnosed or treated. Zika virus presents another equally pressing challenge. Detecting infection early can help identify pregnancies at risk of severe congenital complications, including microcephaly.
Bashir’s team sought to address a longstanding bottleneck in point-of-care diagnostics. While molecular detection technologies have progressed rapidly, sample preparation has remained heavily dependent on centralized laboratories. Diagnosing viral infections from whole blood samples typically requires centrifugation, extraction and purification steps requiring specialized equipment and trained personnel, followed by cold storage and transport. For techniques such as RT-PCR, preparation can account for up to 90% of hands-on processing time.
The new method bypasses these steps by drying the blood sample in a way that captures and stabilizes the target RNA molecules. RNA amplification can then be performed directly on the sample using dried primers and reagents, eliminating the need for cold-chain logistics.
“Throughout the entire diagnostic workflow, only a simple heater is needed for both preparation and amplification, along with a compact, low-cost fluorescence reader to detect the signal,” said Bashir. “This platform maintains accuracy comparable to standard-of-care methods while substantially improving accessibility and availability.”
The system can also support multiplexed detection, allowing multiple viral targets to be identified from a single sample. In laboratory tests, the researchers reported sensitivity down to 1 IU per microliter for hepatitis C virus and 10 copies per microliter for Zika virus, with performance comparable to that of more intensive sample preparation methods.
“Our dried blood–based diagnostic platform addresses the long-standing bottleneck of sample preparation by enabling direct RNA detection from whole blood, combining simplicity, sensitivity and deployability to realize the full potential of true POC diagnostics in both high-resource and low-resource settings,” said Bashir.
Reference
Jongwon Lim et al., Amplification of RNA for identification of Zika and HCV in whole blood. Sci. Adv., 2026, Vol. 12, Issue 6. DOI:10.1126/sciadv.aeb6129
Abstract
Direct RNA amplification from whole blood is fundamentally limited by rapid enzymatic degradation and inhibitory matrix effects. Here, we present a blood drying protocol that enables sensitive and robust RNA detection without the need for extraction, purification, or cold-chain logistics. Using whole blood, the platform achieves high detection sensitivity, down to 10 copies per microliter for Zika virus and 1 international unit per microliter for hepatitis C virus (HCV). We further demonstrate that the protocol can be scaled to larger blood volumes and achieve single-copy sensitivity without any sample loss. This is accomplished through thermal treatments of the sample combined with a primer-limited reverse transcription step, which together stabilize RNA within a dried blood matrix and permit spatially resolved enzymatic amplification. The system supports multiplexed detection from a single sample, enabling simultaneous identification of multiple targets. Separately, we introduce a concept wherein the very few copies of the preserved RNA within the matrix can be accessed repeatedly for molecular analysis. Furthermore, we demonstrated the detection of Zika and HCV using a portable fluorometer for point-of-care (POC) uses. With lyophilized reagents and minimal instrumentation such as a heater and an inexpensive portable fluorometer, this platform enables robust, reusable, and field-deployable diagnostics, advancing toward truly accessible on-site RNA testing in urgent care or low-resource settings from whole blood.