Implementation of FTA Elute Card for Viral RNA Storage and Cost‐Effective Wastewater Surveillance

Wastewater‐based epidemiology (WBE) has emerged as a significant tool for early infection detection during the COVID‐19 pandemic, enabling timely diagnosis and effective control. However, conventional methods for sample transport and storage rely on cold chain logistics, which increase costs and limit accessibility. This study presented a portable and user‐friendly strategy for room‐temperature storage of RNA in wastewater using FTA Elute cards. Quantitative reverse transcription polymerase chain reaction (RT‐qPCR) analysis demonstrated a 15.4% recovery of the original RNA with cards, compared to only 0.5% recovery without cards. Stability assessments under room temperature, ‐4 °C, and ‐20 °C confirmed that RNA retained detectability for over one month, with enhanced preservation at lower temperatures. Furthermore, FTA Elute cards exhibited good recovery for SARS‐CoV‐2, influenza A, and influenza B in spiked wastewater. This work provides a promising solution for RNA preservation and transport in environmental matrices without cold chain dependency.