Final answer:
Antibodies are known to be gamma globulins thanks to protein electrophoresis, a technique pioneered by Arne Tiselius and Elvin Kabat, which allowed the identification and categorization of serum proteins including antibodies.
Step-by-step explanation:
We know that antibodies are gamma globulins through the use of electrophoresis, specifically protein electrophoresis. Swedish biochemist Arne Tiselius and American immunologist Elvin Kabat employed this technique to show that antibodies migrated with gamma globulins. By applying an electric charge to serum proteins within an alkaline buffer solution, proteins including antibodies could be separated and identified based on their movement towards the anode. Gamma globulins, being one of the fractions that move at a different rate compared to others, stand out in the protein profile. This distinction between gamma globulins and other proteins like albumin and fibrinogen emerged as distinct, separable bands on the gel, allowing for a precise categorization of antibodies.
Moreover, protein electrophoresis has been crucial in medical diagnostics, particularly in the identification of abnormal immunoglobulin proteins in the serum of multiple myeloma patients due to their unique protein electrophoresis patterns.