[1] In 1926, Aschner was invited by Professor Israel Kligler to the Hebrew University and engaged in the study of insect-borne diseases.

Four years later, he was awarded a doctorate by the University of Breslau in Germany for his thesis on the symbiont-host relationships between bacteria and flies of the Puppipara group.

He then joined the Department of Hygiene and Bacteriology at the Hebrew University and lived in the Neve Yaakov settlement.

[3][4] During the armistice of the War of Independence, Aschner volunteered for the Science Corps ("Hemed") and worked with other scientists on preparing vaccines against typhus.

Along with Professor Carl Reich and others, he discovered a new species of algae (Prymnesium parvum) in 1946 and identified it as the cause of fish mortality in fishponds.