The Widal test is a serological test used to diagnose typhoid fever and paratyphoid fever. It detects the presence of specific antibodies (agglutinins) in the blood of an individual against the antigens of the bacteria Salmonella typhi and Salmonella paratyphi. The test involves mixing a sample of the patient's serum with antigens derived from the bacteria. If the patient has been infected, their serum will contain antibodies that will agglutinate, or clump, the antigens.

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A "Vitamin B12 Test" measures the level of vitamin B12 in your blood to assess overall health and diagnose deficiencies. Vitamin B12 is crucial for nerve function, red blood cell production, and DNA synthesis. Low levels can lead to symptoms like fatigue, weakness, and neurological issues. This test helps in identifying deficiencies early, enabling timely treatment through dietary adjustments or supplements.

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