The absence of tuberculosis bacilli in the sputum test for tuberculosis, i.e. sputum antacid bacillus smear, may be due to the fact that the sputum retained does not meet the criteria. In addition, the sputum bacillus smear is not necessary for the diagnosis of TB and is less sensitive than the nucleic acid amplification (NAA) test. Sputum can be obtained by self-coughing or induced sputum. Patients providing sputum samples should be aware that nasopharyngeal secretions and saliva are not sputum. Sputum should be from the lower respiratory tract and a minimum of 5-10mL should be collected to achieve adequate diagnostic yield. At least 3 separate sputum samples (at least 1 morning sample) should be collected consecutively at 8-24 hour intervals, but generally two specimens are sufficient for diagnosis. Even if the smear of the first or second sample is positive, it is useful to obtain three samples that can be used for culture. If sputum samples are collected in a healthcare facility, this should be done in an isolation room or an area with appropriate environmental controls. If tuberculosis has been diagnosed, it is recommended to follow the doctor’s advice to receive standardized, full course of anti-tuberculosis treatment and not to stop the medication without authorization.