This research investigates different methods – covalent and non-covalent (streptavidin-biotin) coupling – for attaching capture probes to microbeads used in miRNA detection assays. The key finding is that the non-covalent method yields smoother melting curves and significantly higher hybridization efficiency (90% vs 60% for covalent binding). This seemingly technical detail has important implications for developing robust and reliable bioanalytical tests, particularly those targeting microRNAs as biomarkers for neurodegenerative diseases or other conditions. The variability observed in the covalent coupling method, likely due to secondary amines on the oligonucleotides affecting melting behavior, introduces potential inconsistencies in test results. Smoother melting curves achieved with non-covalent coupling suggest more consistent and predictable binding of target miRNAs to the microbeads. This translates directly into improved analytical sensitivity – meaning the ability to detect even low concentrations of miRNA biomarkers – and greater accuracy in quantification. For bioanalytical tests intended for clinical diagnostics or biomedical research, these improvements are crucial. Reliable detection of subtle changes in miRNA levels can be vital for early disease diagnosis, monitoring treatment response, or understanding disease progression. By optimizing the immobilization strategy on microbeads to ensure efficient and consistent hybridization, this study contributes to developing more dependable and sensitive bioanalytical tools that can ultimately advance our ability to diagnose and manage a wide range of diseases.

Conference venue Zeughaus