Identifying and quantifying apoptosis: a growth industry in the face of death.

Apoptosis remains one of the hottest topics in cell biology, and great strides are being made in unravelling the complex interplay between the various regulatory molecules, particularly between the mammalian homologues of the nematode Caenorhabditis elegans death regulatory proteins Ced-3, Ced-4 and Ced-9. Curiously, the relative merits of the seemingly simple methodologies to visualize and quantify apoptosis still provoke considerable debate. Many are based on the ability to detect DNA breaks by enzyme-mediated addition of labelled nucleotides, but the capricious nature of many of the available labelling kits, combined with a lack of true specificity, continues to fuel the search for more reliable apoptosis 'markers'. Copyright 1999 John Wiley & Sons, Ltd.