Prof. Martin Kessel¹ & Prof. Ehud Skutelsky^2  
1 Prof. Emeritus, the Hebrew University of Jerusalem and the National Cancer Institute, the National institutes of Health, USA.
² Prof. Emeritus Tel Aviv University Sackler School of Medicine

David’s major scientific achievement was the establishment in 1955 of the field of Biological Electron Microscopy in Israel. David was elected the founding President of the Israel Society of Microscopy (formerly the Israel Society of Electron Microscopy) in 1964 and was an Honorary Member of the Society.

David’s first connection to electron microscopy came during his studies as a medical student at the University of Geneva. There, in 1949-50, together with biophysicist Eduard Kellenberger, David designed and built an early ultramicrotome capable of cutting sections as thin as 0.04nm of fixed and epoxy resin embedded biological material [1]. Thin sections were essential to allow the penetration of electrons in order to record images of the observed biological structures.

The first electron microscope in Israel an RCA EMU2A had arrived in 1949 after being donated to the Weizmann Institute by the president of the Radio Corporation of America, David Sarnoff, in honor of Chaim Weizmann’s 70th birthday.

In 1952 the electron microscope, was installed in the Ziskind Building, and for some time the Institute’s scientists tried to operate the microscope, but with little success. The microscope remained non-operational until 1955 when David, by then an MD in the Israel Air Force based in Tel Nof, was recruited to establish and operate the EM Unit as Head of the new Section of Ultrastructure Research. At the same time Yehuda Marikovsky, then Head of the Israel Air Force Medical Lab at Tel Nof, joined David Danon at the EM Unit where they worked in close collaboration over the next 35 years. During this time Marikovsky obtained his Ph.D. degree at the Weizmann Institute.

A second RCA microscope (model EMU3G), was installed in 1962, and in 1963 both microscopes were transferred to the new Ullman Building’s Department of Ultrastructure Research. Newer JEOL electron microscopes were subsequently added to the Department. A JEOL JEM100B continued to be operated until recently in the Department of Biological Chemistry by Yehuda Marikovsky, now an emeritus Research Fellow. One of Danon’s early and most successful Ph.D. students was Ehud Skutelsky, who established his own lab at the Tel Aviv University Sackler School of Medicine.

David’s laboratory was at the forefront of research in biological ultrastructure. His main scientific interest was in the biology of aging. He used mammalian red blood cells as a model for study age-related modifications of structural, biochemical and biophysical properties of cell membranes. He designed procedures for separation of old and young erythrocytes, and invented unique instrumentation, the Fragiligraph,for measuring osmotic fragility and aglutinability of cells. Due to his achievements he was nominated as the head of the Center of Gerontology Research in the Weizmann Institute of Science, and in 1975 he was elected as the President of the International Society of Gerontology. During 1979-1987 he served as the chief scientist of the Ministry of Health in Israel

David’s enthusiasm for science and his exuberant personality drew many young scientists to his lab who went on to establish their own electron microscope research laboratories in Israel such as Itzhak Ohad at the Dept. of Biological Chemistry at the Hebrew University.

In 1976 the Israel Society of Electron Microscopy hosted the 6th European Congress on Electron Microscopy at the Binynei Ha’ooma in Jerusalem. This highly successful meeting of which David was the President and dominant presence, brought to Israel an unprecedented number of the world’s leading scientists in the fields of Biological and Materials Science electron microscopy. The unique atmosphere at the Congress placed Israel at the center of research using the electron microscope.

In retirement David continued to be active in science and working with the Israeli National Blood Service, Magen David Adom, he developed the technology for CureXcell. This technology was subsequently acquired by MacroCure, which enhanced the product’s development. CureXcell has been approved for use by the Israeli Ministry of Health for the treatment of chronic wounds and was recently made a part of the Israel National Health Insurance list of reimbursable drugs.

This appreciation has focused on David’s contribution to the biological sciences and has not detailed David’s many other siginificant lifetime achievements.

David will be sorely missed but his pioneering spirit which has spawned generations of highly successful scientists in the field of electron microscopy in Israel, will ensure that his legacy continues to live on.
  
[1] Danon D. An instrument to trim plastic Specimen blocks for electron microscopy prior to sectioning. J Biophys Biochem Cytol. 1961 Mar; 9: 726–8