Test Directory

Gastric washings (Mycobacteria only)

Containers - Adult

150ml Sterile Urine Container
Additive per Container


Containers - Child

150ml Sterile Urine Container
Volume Range

As adult

Laboratory Site

51 Little France Crescent
Old Dalkeith Road
EH16 4SA
Telephone (Bacteriology): 0131 242 6021 OOH Bleep 2900
Scottish Mycobacteria Reference Lab
Microbiology Department
Royal Infirmary of Edinburgh
Little France Crescent
Edinburgh EH16 4SA
Telephone: 0131 242 6022/3 (Lab) 0131 242 6016 (Office)

Transport arrangements

Transport as soon as is practicable.

Sample storage arrangements

Don't delay in transporting to the lab; stomach acid will cause deterioration of the organisms.

Special instructions for collection

Useful: in patients with suspected mycobacterial lung infection who are not able to expectorate sputum but are suspected of swallowing respiratory secretions. Particularly useful in children. This is not suitable for routine bacterial sputum culture and sensitivities.

Note induced sputum is preferable to gastric washings, if available. The patient should be nil by mouth from midnight, and samples collected first thing in the morning before breakfast. Insert the largest bore NG tube that is comfortable without lubrication (because it's bacteriostatic). Aspirate stomach contents: if less than 10mls of mucus is collected, then instill 10-20mls of sterile water (not saline) down the NG tube and quickly reaspirate before putting in specimen container. Collect 3 separate gastric washings this way on three consecutive days and transport to the laboratory quickly to avoid stomach acid breaking down the sample.

How to request

Via Trak ("Mycobacteria TB Ix - Fluids" then specify (Aspirate,gastric Mycobact) or via request form.


0900-1700, Monday - Friday (RIE)

Anticipated turnaround

Microscopy: 1 day. Culture: 4 - 6 weeks. 

What happens if the result is positive or abnormal

Telephoned by microbiologist.

General additional information

Note that microscopy of gastric washings can be misleading as other acid-fast bacilli are normally present in the stomach. 

For further information, please see Scottish Mycobacteria Reference Laboratory