Dr. Aser Rothstein

Apr 29, 1918 — Aug 06, 2015

Aser Rothstein died in Guelph, Ont., on July 4 at the age of 97.

He was born in Vancouver on April 29, 1918. His father, Sam, had been smuggled out of prerevolutionary Russia at the age of 16 to join an older brother in New York. His mother, Etta (née Wiseman), had emigrated from the Austro-Hungarian Empire. The family ran several businesses, including trading in scrap metal and selling burlap bags.

Aser Rothstein became a top physiologist and cell specialist by way of pique. His university physics professor wasn’t impressed when he was often late for the early morning class, and deployed a series of caustic remarks to predict that his sleepy student would surely receive a BAC (“Bounced at Christmas”) degree. Instead, the student wrote a perfect exam in his first semester, scored 94 per cent on his final and was invited by the now-friendly professor to major in physics.

Globally, Dr. Rothstein achieved renown for his contributions to the fields of cellular physiology and toxicology. In Canada, he made his mark as director for 14 years of the Research Institute at Toronto’s Hospital for Sick Children, which he grew to one of the premier pediatric research establishments in the world.

His own research focused on cells, specifically how and why the plasma membranes that encase cells allow certain substances to pass through, but not others. Membrane research has important implications for a host of issues, including cancer and organ transplants, and genetic diseases such as cystic fibrosis and muscular dystrophy.

One of his notable achievements, in the late 1960s, was to identify the protein responsible for anion transport in red blood cells (an anion is a negatively charged ion). With pioneering experiments using radioisotopes, he found a chemical that would bind to a specific molecule, and, using radioactivity, separated all the proteins from the red cells, finding the one responsible for anion transport.

Dr. Rothstein was a passionate researcher. He wrote some 300 papers in his lifetime, and the title of his memoir is My Love Affair With Membranes.

Dr. Rothstein was a Weizmann supporter and Board Member. He served on the Institute’s Board of Governors since 1987 to 1997 and on the Scientific and Academic Advisory Committee since 1987 to 1994.

He leaves his wife, Evelyn; children Steven, Sharon and David; a brother, Mort; seven grandchildren and five great-grandchildren.