Are all antibodies proteins?

Antibodies are all proteins. Antibodies, also known as immunoglobulins, are produced by B lymphocytes or memory cells of the immune system after proliferation and differentiation into plasma cells upon antigen stimulation. Their primary function is to specifically bind with the corresponding antigens, thereby exerting immune effects, such as neutralizing pathogen toxins, facilitating pathogen clearance, and mediating immune regulation. Since the chemical nature of antibodies is protein, they possess all the fundamental properties of proteins, such as amphoteric dissociation, colloidal properties, denaturation, precipitation, color reactions, and ultraviolet absorption. These characteristics make antibodies highly valuable in biological and medical research, including applications in disease diagnosis, treatment, and prevention.