Following his Ph.D., Trager joined the lab of
Rudolf Glaser in the Department of Animal and Plant Pathology in the
Princeton, New Jersey division of the
Rockefeller Institute for Medical Research as a
postdoctoral fellow. During
World War II, Trager served as a captain in the
US Army Sanitary Corps supervising clinical trials with the antimalarial
atabrine. In the 1970s Trager and a postdoctoral fellow
James B. Jensen performed the work for which Trager is best known: the cultivation of
P. falciparum. Trager also worked sporadically throughout his career on
kinetoplastid parasites. He showed that the intracellular stage of
Leishmania donovani could be cultured for several days, and established a
tsetse fly tissue culture system to grow all the life stages of
Trypanosoma vivax. He also developed a continuous culture system for the lizard-infecting parasite
Leishmania tarentolae. In 1980, Trager transitioned to the role of
emeritus professor at Rockefeller University. ==Personal life==