The diagnosis for tuberculosis is done through series of live blood testing uder darkfield light microscope. Another test to find out the presence of TB infection is the tuberculin skin test. This is the widely used by most medical doctors because of its accuracy. After the darkfield light microscope testing other factors are also considered. The person might have acquired TB from work and through exposure and close contact with a person who has TB can be considered a risk factor. The four factors that are very important in the diagnosis of Tuberculosis are the medical history of the patient, the tuberculin skin test, chest x-ray and the blood examination through darkfield light microscope.
The medical history of the patient includes past records of the disease and it can also be achieved by asking the patient if he has been exposed to a person who is suffering from TB disease. The medical doctors are also observing symptoms that show pulmonary tuberculosis infection such as coughing, painful coughing and breathing and coughing with blood. Other symptoms that are observed on the first phase of TB infection are weight loss, fatigue, malaise, fever and sweating at night. If the person is suffering from the abovementioned symptoms it is advised to let them undergo series of tests that can evaluate the condition of the patient.

The tuberculin skin test is the next procedure that is conducted by medical doctors for the patient who are experiencing symptoms of TB.  The chest x-ray should be conducted after the tuberculin skin test to rule out the chances of pulmonary Tuberculosis disease. The last test could be acquired through blood testing through darkfield light microscope, though bacteriologic test can also be performed using sputum specimen and examined under a microscope to check if it contains acid-fast bacilli. The confirmation of the presence of Acid-fast bacilli is then cultured to check the presence of M. tuberculosis that confirms tuberculosis disease. This test is also used to find out what appropriate drug should be administered to the patient suffering tuberculosis disease. Here is a link to the article