Recent advances in single-nucleotide variant assay: From in vitro detection to in vivo imaging

Single-nucleotide variants (SNVs) are single base changes that appear in the coding regions and non-coding regions. SNVs are closely related to multiple physiological and pathological processes, and may act as important biomarkers. Consequently, accurate and sensitive identification of SNVs is critical for medical diagnosis and disease treatment. In recent years, a series of novel SNV detection methods have been developed, but an overview of in vitro detection and in vivo imaging of SNVs is lacking. Herein, we review the emerging methods for in vitro and in vivo SNV assays in the past few years. The in vitro SNV detection methods are categorized into five types including fluorescent, colorimetric, electrochemical, electrochemiluminescent, and chemiluminescent methods, while the in vivo SNV assays mainly rely on fluorescence imaging. We summarize the characteristics, principles, performances, and applications of these methods, and discuss the existing challenges and trends in this area.