This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Forensic Medicine
ABO antigen are found in all except ? 
Select and explain. 
A. Saliva, B. Sweat, C. CSF, D. Gastric juice
C: CSF
Answer: C: CSF 
Explanation: Ans. is 'c' i.e., CSF ABO antigen can be demenstrated in all body fluids except CSF"_________ Reddy. They are detected in almost all tissues, but not found in - Nerve tissue Epithelium Skin appendages Bone Cailage