Quantum dot-based mortalin staining as a visual assay for detection of induced senescence in cancer cells

Quantum dots (QDs) are fluorescent nanocrystals that are emerging as fine alternatives to the conventional organic dyes. They have several advantages including greater photostability and a wider range of excitation-emission wavelengths. By using mortalin staining as a model, we initially demonstrated that the QDs are more stable and provide better resolution in protein imaging in fixed cells. With the help of an internalizing antibody, we generated internalizing QD (i-QD) and demonstrated its inertness to cell replication, structure, and viability. Based on the superior resolution, stability and inertness, we propose the use of QD staining of mortalin as a cell-based visual assay to screen for senescence-inducing drugs, proteins, and siRNAs.