Storing a sputum sample

Content

Storage conditions of sputum sample can effect the test results.

Sputum samples should be transported to the laboratory as soon as possible after collection.
It is the responsibility of Laboratory Technician (LT) and Senior TB Laboratory Supervisor (STLS) to ensure proper storage and transport of sputum specimens.
Sputum is stored to preserve the specimen quality.
The stored sputum samples should not be frozen.

Storage of Sputum Samples

For microscopy

For smear microscopy, sputum specimens should be examined on the same day and not later than 2 days after collection.
If delay is unavoidable, the sputum collected should be stored in a cool place/ refrigerated at 4°C to inhibit the growth of unwanted microorganisms.
Stored sputum samples should be protected from light and heat to prevent liquefaction of the sample, else it makes the selection of mucopurulent part of the sample difficult.
Samples received over holidays/weekends should be stored in a cool place/ refrigerated at 4°C.

For liquid culture

Sputum should be stored in a cool place/ refrigerated at 4°C to inhibit the growth of unwanted microorganisms; not later than 3 days after collection.

For molecular tests - Nucleic Acid Amplification Test (NAAT) and Line Probe Assay (LPA)

Sputum must be stored by refrigerating at 4°C to inhibit the growth of unwanted microorganisms and transported in cool chain to the nearest molecular laboratory. It should not be stored beyond one week at 4°C.

Resources

Assessment

Question

Answer 1

Answer 2

Answer 3

Answer 4

Correct answer

Correct explanation

Page id

Part of Pre-test

Part of Post-test

The sputum collected expecting a time delay for processing should be stored in cool place/ refrigerated at 4°C.

True

False

The sputum collected expecting a time delay for processing should be stored in cool place/ refrigerated at 4°C.

Yes

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