Rabbit anti-human calcitonin is a refined immunoglobulinfraction derived from rabbit serum. Contaminatingantibodies have been removed through solid-phaseabsorption. Research indicates that the antibody interactswith human calcitonin and identifies C-cells in healthythyroid tissue. It is very beneficial in distinguishingmedullary carcinoma from papillary and follicular thyroidcancers. When utilized alongside an anti-thyroglobulinantibody, the majority of medullary carcinomas exhibitpositivity for calcitonin, but most papillary and follicularthyroid cancers are negative.