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The culture and sensitivity test is to grow the bacteria/fungus causing the disease .The samples are selected based on the system involved , i mean if patient has cough
then sputum is taken and if burning urination then urine is taken as the sample and the bacteria isolated. In some cases where the sample fails to grow the infecting bacteria then blood is take as sample .The theory is simple , as the blood moves all over the entire body the possible infecting bacteria or the fungus can be isolated and the sensitivity tests show which antibiotics will kill the bacteria better and put on the patient.
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