Tracking the movement and location of living cells both in vitro and in vivo is of importance in various branches of life sciences. Particularly in stem cell research, robust and reliable tracking of transplanted cells is essential towards detailed understanding of their development, fate, and contribution to regenerating tissues. LuminX Tracking Kit™ (LTK) is designed to serve the purpose.

Current methods used to fluorescently tag cells have been limited by short-term signal duration, auto-fluorescence background and manipulations of fluorescent gene expression. LTK are biocompatible, non-toxic, no genetic modification requirement and have single-cell detection sensitivity. Furthermore, LTK can achieve background-free image, non-invasive long-term tracking in vivo and permit quantification of cell numbers at any anatomic location. LTK contains a high-density ensemble of negatively charged nitrogen-vacancy (NV−) color centers (XTagTM) as built-in fluorophores, which are red fluorescent, perfectly photostable, and can be detected with high sensitivity in cells and tissues by fluorescence time gating. These distinctive characteristics make them as optimal candidates for permanent live cell bioimaging experiments and well suited for long-term cell tracking applications in vitro and in vivo.