Linus Pauling's reputation rests on his many and diverse accomplishments that spanned a better part of the twentieth century. His undertakings include his fundamental contributions to chemistry (the nature of the chemical bond and the structure of proteins), his advocacy for world peace, and his promotion of Vitamin C, to name a few. Pauling's disparate scientific career and political statements can be viewed through his preoccupation with blood – specifically, his interest in hemoglobin and a disease of human hemoglobin, sickle cell anemia.

In 1935 Pauling conducted his first analysis of hemoglobin. For the next ten years he performed various scientific experiments on hemoglobin and in immunology, which gave him unique knowledge and allowed him to contribute significantly to understanding the chemical reaction occurring in the blood of people suffering from sickle cell anemia. His diverse scientific background led him to devise a theory of the sickling process and define sickle cell anemia as a molecular disease. Pauling and three colleagues wrote their celebrated article "Sickle Cell Anemia, a Molecular Disease" in 1949.

In the forty-five years after this publication, Pauling continually drew upon his knowledge of normal and abnormal hemoglobin. Although sickle cell anemia was peripheral to most of Pauling's scientific work after 1949, he integrated sickle cell hemoglobin into many of his subsequent projects whether scientific, social, or political. For example, he used hemoglobin in his scientific research on the Molecular Evolutionary Clock and in orthomolecular medicine. He also discussed social and political aspects of sickle cell anemia by promoting genetic counseling, and by drawing analogies between mutagenic effects of nuclear fallout and abnormal hemoglobin.

By analyzing his use of hemoglobin and sickle cell anemia, a common thread develops that connects most of his endeavors from the mid-1930s until his death in 1994. All in all, the role of these two entities in Pauling's work demonstrates versatility in his use of normal and abnormal hemoglobin, and continuity among his research and crusades over his lifetime.