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': 'Hepatitis A virus is best diagnosed by \nSelect and explain. \nA. IgM antibodies in serum, B. Isolation from stool, C. Culture from blood, D. Isolation from bile', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. is \'a\' i.e., IgM antibodies in serum Lab diagnosis of HAV . "Detection of IgM - specific anti-HAV in the blood of an acutely infected patient confirms the diagnosis of hepatitis A" . IgM appears in acute phase, peaking about 2 weeks after elevation of liver enzymes and becomes undetectable within 3-6 months. . ELISA is the method of choice for measuring antibodies. Diagnosis can also be established by detection of virus in the stool from about 2 weeks prior to the onset of jaundice up to 2 weeks after. "But these tests for detection of HAV, are not widely available or useful in practice".', 'role': 'assistant'}]