Who today can imagine modern immunology without cell sorting or fluorescence-labeled antibodies? How would simple blood profiling be done? How could the extraordinary intricacies of lineages and sublineages of the immune system be delineated, or the diversity of cell types in a tumor be understood? How could the discoveries that HIV-1 specifically attacks CD4+ T cells and that the onset of AIDS is caused by the loss of such cells have been made? Len's discoveries grew an industry and drove innovation via application of the tools he developed that eventually reached far beyond immunologists to the international biomedical research community.
Len, who grew up in Brooklyn, New York, finished his Ph.D. at the California Institute of Technology in 1955, moved to the Pasteur Institut to work with Nobel Prize winner Jacques Monod, then returned to the US after his postdoctoral fellowship to work at the US National Institutes of Health. In 1959, Len moved to Stanford University to initiate work on mammalian cells that would later lead to the revolution in cellular analysis for which Len is best known. Although it is just one of his many achievements, his seminal contribution is, of course, the fluorescence-activated cell sorter and the amazing research culture it engendered. In the very same basement where Nobel Prize winner Josh Lederberg had a team developing an automated laboratory for the Viking Lander to search for life on Mars, Len Herzenberg was developing his 'space-age' cell sorter. Len would often remark how critical it was to the development of fluorescence-activated cell sorting to have not only the support of Lederberg but also the intellectual environment the Viking engineering teams provided—space age, indeed!
