Alexander Catsch (also Katsch; 1913–1976) was a German-Russian medical doctor and radiation biologist. Up to the end of World War II, he worked in Nikolaj Vladimirovich Timefeev-Resovskij's Abteilung für Experimentelle Genetik at the Kaiser-Wilhelm-Institut für Hirnforschung (KWIH, Kaiser Wilhelm Institute for Brain Research). He was taken prisoner by the Russians at the close of World War II. Initially, he worked in Nikolaus Riehl's group at Plant No. 12 in Ehlektrostal’, but at the end of 1947 was sent to work in Sungul' at a sharshka known under the cover name Ob’ekt 0211. At the Sungul' facility, he again worked in biological research department under the direction of Timofeev-Resovskij. When Catsch returned to Germany in the mid-1950s, he fled to the West. He worked at the Biophysikal