Fritz Heinz Bach (5 April 1934 – 14 August 2011) was an Austrian-born American transplant physician and immunobiologist. He was considered one of the pioneers in the field of transplant immunology. Being born in a Jewish family in Vienna, Bach fled Nazism at an early age. He was moved to England in the Kindertransport, and later with his family made the journey overseas to the United States. He obtained a scholarship to study at Harvard and continued his studies until graduating in 1960. Soon afterwards, Bach made his first contributions to the field of transplant immunology. One of his main achievements was the development of the mixed lymphocyte culture (MLC) test, which furthered research on preventing transplant rejection. Bach spent the main part of his career at University of Wiscons