Tuberculosis Sputum Specimens

Suspicion of Active Tuberculosis

Notify the Health Department of suspected active tuberculosis or positive AFB (acid-fast bacilli) smears or cultures.

Patients Without Insurance

  • Contact the Health Department. They may contact the patient and arrange to drop off and pick up sputum collection cups.
  • Testing will be done at the Washington State Public Health Lab (PHL) at no charge to the patient.

Patients with Insurance


  • Use a sterile container, like a sputum or urine cup, and mark the container at the 5 mL level.
  • Educate the patient to expectorate at least 5 mLs (1 tsp) of sputum.
  • Label each container with the date of collection, the patient’s name, date of birth and other information as required by the laboratory.

Patient Instructions

  • Instruct the patient to collect specimens on three consecutive days, with at least two specimens collected in the early morning (secretions build up while the patient is sleeping).
  • You may find this Sputum Collection Patient Education Sheet helpful.


  • Submit each specimen to the laboratory for “AFB (acid-fast bacilli) smear and culture”


  • Depending on the laboratory, smear results are generally available within 24 to 48 hours.
  • Depending on the laboratory, final culture results are generally available within six to eight weeks.

Ruling Out Active Tuberculosis

  • Active tuberculosis is ruled out when all final culture results are negative and there is no remaining clinical suspicion.
  • Latent tuberculosis treatment should not be initiated until active tuberculosis has been ruled out.