25 April 1986
Vol 232, Issue 4749

About The Cover

Pseudocolor digitized computer image of fluorescence intensity distribution in human fibroblasts stained with carboxyfluorescein diacetate. Fluorescence in a cell can be bleached with a laser and intercellular communication assayed by rapidly and repeatedly measuring the redistribution of carboxyfluorescein in bleached and unbleached cells. Addition of tumor promoting agents can block the intercellular communication. See page 525. [Margaret H. Wade, Meridian Instruments, Inc., Okemos, Michigan, and James E. Trosko and Melvin Schindler, Michigan State University, East Lansing 48824]