This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology Pa 1 (Immune Response, Antigen-Antibody Reactions, Hypersensitivity, Structure of Immune System, Immunodeficiency Disorders), Subject name: Microbiology
Bence Jones proteins are best described as- 
Select and explain. 
A. u chains, B. g chains, C. Kappa & Lambda chains, D. Fibrin split products
C: Kappa & Lambda chains
Answer: C: Kappa & Lambda chains 
Explanation: Bence Jones protein is a monoclonal globulin protein or immunoglobulin light chain found in the urine, with a molecular weight of 22-24 kDa. Detection of Bence Jones protein may be suggestive of multiple myeloma or Waldenstrom's macroglobulinemia. Bence jones proteins are light chains of immunoglobulins so may occur as Lambda or Kappa forms, but in any patient the chain is either Kappa or Lambda, never both. Fibrin split products are seen in a case of thrombolysis or DVT. m and U are the types of heavy chain.