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: Microbiology
[{'content': 'Congenital syphilis can be best diagnosed by ? \nSelect and explain. \nA. IgM FTA- ABS, B. IgG FTA-ABS, C. VDRL, D. TPI', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. is \'a\' i.e., IgM FTA-ABS Lab diagnosis of congenital syphils . As Ig M does not cross placenta, its presence in neonatal serum confirms congenital syphilis and helps differentiating it from seropositivity due to passively tranfered maternal antibodies. The tests to detect IgM are: . FTA-ABS (19S IgM FTA-ABS) . Syphilis Capita M test "For measurment of Ig M in neonate in whom congenital syphilis is suspected, the syphilis capita M test and the 19S IgM FTA-ABS test are available". - Note - lr/e Harrison says, "No commercially available IgM test is recommeded for evaluation of infant with suspected congenital syphillis". - 1043', 'role': 'assistant'}]