How to collect a sputum sample for a AAFB test

What is an AAFB test?

An acid alcohol fast bacteria (AAFB) test is done to find out if you have tuberculosis (TB) or another infection caused by mycobacteria. Other mycobacteria are a kind of bacteria that are found in water and soil, although they are usually harmless, if they enter your body, they can cause a number of problems, including lung issues.

How do I do the test?

Your health care provider will give you special plastic pots for collecting your sputum (sputum is the mucus that settles in the lower airways of your lungs when you have an infection or a chronic illness. It's also called phlegm).

You will be given three sample pots that will be labelled 1, 2 and 3 as well as bags and forms labelled 1, 2 and 3.

The 3 different sputum samples must be collected around 8 to 24 hours apart, with at least one of them being collected in the early morning.

Please provide your samples in order; sample 1 in pot 1, sample 2 in pot 2 and sample 3 in pot 3. Put the pot and the form in the bag, making sure they all say the same number on them each time you collect a sample. 

Follow these steps carefully:

1. The pot is very clean. Do not open it until you are ready to use it. 
2. As soon as you wake up in the morning (before you eat or drink anything), brush your teeth and rinse your mouth with water. Do not use mouthwash. 
3. Take three deep breaths in through your nose and exhale through pursed lips (bring your lips tightly together so that they form a rounded hole shape), then force a cough.
4. Spit the sputum into the sample pot. 
5. Screw the cap on the pots tightly so they do not leak. Write the date you take the sample on the pot and the request form.
6. Put the pot with the sample in into the bag with the request form the health professional gave to you. Make sure the pot and request forms have your correct details including your name and date of birth.
7. Drop the pot off at your collection point; this may be your health care provider, your GP, clinic or hospital laboratory reception, ideally on the same day you have provided each of the samples. Sputum samples should be quite fresh (less than 1 day old) to get accurate results. 

If you cannot take the sample to the collection point on the same day or you can only cough up sputum in the afternoon or evening, please store the pot in a refrigerator overnight. As soon as possible on the next day, take it to your collection point.

Remember to tell other household members not to open it and keep it out of the reach of children.

How to collect a sputum sample for an AAFB test - patient information leaflet
Version: 1
Revision due: November 2025