Using the photonic toolbox to study chromosomes: 50 years in search of an answer!

Little did I know that when I published our first laser microbeam paper on chromosome surgery in 1969, that 50 years later I would still be doing that—trying to explain the inexplicable result we saw back then. The path to an answer of why cells with partially photon-ablated chromosomes could reproduce and maintain the photon-induced deletion in the clonal population of cells, was a path that was solely possible by the parallel development of additional tools in the photonic toolbox. Development of digital-based imaging technologies, GFP-based molecular fluorescent probes, and an evolution of optical manipulation tools (photonic scissors and tweezers) have been combined to provide a tantalizing answer to the question of why cells can divide and form clones following removal of a segment of their DNA.