ABS 035: Portable miRNA Detection with Ligation-initiated Transcription and CRISPR/Cas12a

Megan Salib ¹, Mina Liao ¹, Jason Berdia ¹, Emily Elassal ¹, Michael Scott ¹, Jeremy Vo ¹, Catherine Spirito ¹, Shannon Hilton ¹

¹ University of Maryland, College Park

The Van Wickle Journal (2026) Volume 2, ABS035

Introduction: Early detection of cancer is important for improving patient prognosis. Rates of cancer incidence and mortality across different regions expose disparities in accessibility of early cancer detection, where the highest mortality rates are found among low- and middle-income communities. miRNAs are promising biomarkers for early cancer screening because they are detectable in peripheral blood and their dysregulation is associated with cancer progression. There is a need for a portable, cost-effective miRNA detection method, since current methods, such as RT-qPCR, require expensive equipment.

Methods: The presence of a target miRNA initiates rolling circle transcription, producing crRNA repeats needed to activate a Cas12a enzyme. Trans-cleavage activity of Cas12a separates cross-linked gold nanoparticles, producing a colorimetric signal. We demonstrated successful performance of the RCT and Cas12a-based assay, and achieved color change via the cross-linking assay. To quantify and heat the assay, we designed and 3D-printed a portable sensor. The single-board computer-controlled device heats eight PCR tubes while a mini camera captures photos in real time. The device then quantifies the color change of each tube by converting the images to the CIELAB colorspace and measuring the delta E.

Results: We demonstrated successful activation of Cas12a in the presence of our target miR-21, and achieved a color change via the cross-linking assay.

Discussion: Combining our RCT and Cas12a-based assay with our custom sensor device would enable rapid detection of miRNA biomarkers.