Takei, Y. et al. Biophys. J. http://dx.doi.org/10.1016/j.bpj.2017.03.024 (2017).

Imaging is a powerful tool for studying chromosome dynamics, but labeling and imaging multiple loci in live cells is technically challenging. To tackle this challenge, Takei et al. developed the 'track first and identify later' strategy for multiplexed chromosome imaging. This approach uses CRISPR–Cas9 to label multiple loci with the green fluorescent protein for live-cell imaging of their dynamics. Following single-color live-cell imaging, cells are fixed, and loci are barcoded using DNA sequential fluorescence in situ hybridization. Thus, the precise identity of each imaged loci, while unknown during imaging, is revealed. A potential caveat is that the loci must remain distinguishable throughout imaging. The researchers demonstrated the method by imaging twelve telomeric loci and recording their distinct dynamic properties.