1969 Press Photo Mouse leukemia virus magnified 150,000 by electron microscope

Virus particle (arrow) which causes leukemia in mice is magnified 150,000 times by electron microscope. Present efforts are directed toward identification of a similar virus in humans suffering from leukemia. So far, a human leukemia virus has yet to be isolated.

Photo is dated 1969.

Photo measures 10 x 8.25 inches.