Cat IgG whole molecule was prepared from normal serum by a multi-step process which includes delipidation, salt fractionation and ion exchange chromatography followed by extensive dialysis against the buffer stated above. Cat IgG whole molecule assayed by immunoelectrophoresis resulted in a single precipitin arc against anti-Cat IgG and anti-Cat Serum. Secreted as part of the adaptive immune response by plasma B cells, immunoglobulin G constitutes 75% of serum immunoglobulins. Immunoglobulin G binds to viruses, bacteria, as well as fungi and facilitates their destruction or neutralization via agglutination (and thereby immobilizing them), activation of the compliment cascade, and opsinization for phagocytosis. The whole IgG molecule possesses both the F(c) region, recognized by high-afinity Fc receptor proteins, as well as the F(ab) region possessing the epitope-recognition site. Both heavy and light chains of the antibody molecule are present. Cat IgG whole molecule is ideal for researchers in Cancer, Immunology, and Cell Biology.