In Situ Amplification-Based Imaging of RNA in Living Cells

Owing to its important physiological functions, especially as molecular biomarkers of diseases, RNA is an important focus of biomedicine and biochemical sensing. Signal amplification detection has been put forward because of the need for accurate identification of RNA at low expression levels, which is significant for the early diagnosis and therapy of malignant diseases. However, conventional amplification methods for RNA analysis depend on the use of enzymes, fixation of cells, and thermal cycling, which confine their performance to cell lysates or dead cells, thus the imaging of RNA in living cells remained until recently little explored. In recent years, the advance of isothermal amplification of nucleic acids has opened paths for meeting this need in living cells. This minireview tracks the development of in situ amplification assays for RNAs in living cells, and highlights the potential challenges facing this field, aiming to improve the development of in vivo isothermal amplification as well as usher in new frontiers in this fertile research area.