After working briefly in industry Grabar became chief (chef de laboratoire) of a clinical laboratory at the
University of Strasbourg from 1926‑1930. There he began doing medical research on kidney function with professor Leon Blum. Grabar received his doctorate in 1930, having worked on
uremia and
salt deficiency and published "Azotemie par manque de sel" (Uremia due to salt deficiency). In 1937-1938 Grabar was a
Rockefeller Foundation Fellow at
Columbia University in New York, USA. There he met the founder of quantitative immunology,
Michael Heidelberger and found his vocation for the relatively new science of immunology. In 1954, Grabar was president of the (SFBBM, originally named the Société de Chimie Biologique). In 1966, Pierre Grabar founded the (SFI), serving as its first president from 1966-1969. From 1960 to 1968 Grabar was director of l'Institut de recherches sur le cancer (
Cancer Research Institute) of the Centre National de la Recherche Scientifique (CNRS) in
Villejuif, France where he carried out research on proteins and cancer. In 1969, Grabar returned to the Pasteur Institute, where he was named honorary chief (chef de service honoraire). ==Immuno-electrophoretic analysis==