Microlaser particles have emerged as unique optical probes for single-cell tracking. However, due to inherent directionality of laser emissions, cell tracking with laser particles suffers from frequent loss of cell traces. Recently, scientists at Harvard Medical School and Peking University placed omnidirectional visible laser particles into live cells, and demonstrated continuous spatial tracking of single cells. The technique will open new avenues for large-scale single-cell analysis in the study of cellular heterogeneity.