Reviewed on : 20 Jan 2022

Reviewed by : Coventry and Warwickshire Pathology Services & Gateway Editor

Expires : 20 Jan 2024

The following is an excerpt from the Pathology Directory published elsewhere on GP Gateway

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Pus, Swabs, Aspirates, Biopsies

a. Pus

NB where there is both histopathological and microbiological examination required, a portion of the sample for Microbiology must be collected into a white-topped sterile container WITHOUT FORMALIN.

Pus should be sent in preference to a swab and in some cases e.g. suspected tuberculosis or actinomycosis, pus should always be sent if present.

Samples are sent in sterile universal containers. DO NOT ADD FORMALIN.

b. Swabs

Where there is insufficient material to send pus, the site may be sampled using a swab.

As much material as possible should be taken up on the swab by rubbing it gently over the affected area and rotating it at the same time.

The swab should then be placed in a tube of transport medium, which allows the survival of the more delicate organisms that might otherwise be missed. (Dry swabs are not used).

c. Nose swabs

When sampling the anterior nares i.e. a suspected MRSA carrier, it is important that the swab should be pre-moistened in sterile saline.

d. Fluid aspirates, biopsy specimens etc

Aspirated fluids, such as bursa/synovial fluids etc, should be sent in a sterile Universal container, separate from the portions set aside for histological, cytological or biochemical investigation.

If tuberculosis is a possibility this should be stated on the request form, so that TB culture may be performed.

Biopsy specimens should be sent similarly.

It is most important that the portion for microbiological examination is received FRESH AND FREE FROM FORMALIN.

The same consideration about possible tuberculosis applies as above.