Sterile Samples (e.g. CSF, abscess pus, synovial fluid, tissue biopsies)

A sterile sample collected as described below will give your patient the best result.

Specimen types you should send:

  • Sterile body fluid samples (s. list below) obtained for microbiological culture
  • Samples should be collected from sterile sites using aseptic techniques.
  • Please indicate if tuberculosis is a possible diagnosis when collecting samples from sterile sites.

How to Collect the Sample

  • Disinfect the skin site thoroughly prior to puncture or incision.
  • If necessary use sterile gloves and sterile drapes around the incision or puncture site.
  • Aspirate the body fluid into a syringe and decant the fluid into the sterile container.
  • Screw the lid back on the container and make sure that it does not leak.


  • Label the specimen with patient information (First Name, Surname, DoB, location, physician, time and date) and also fill in those details on the request form.
  • A good history on the request form helps the laboratory tremendously.
  • In particular note the likelihood of specific diseases on the form which you would like us to look for. Tuberculosis is an often under-considered differential diagnosis but requires additional culture in our laboratory.

List of samples that fall under above sampling recommendations

  • Cerebrospinal fluid (CSF)
  • Abscess aspirates (from various anatomical locations)
  • Pleural fluid
  • Ascites 
  • Bone biopsy
  • Tissue biopsy (from sterile anatomical sites e.g. brain, liver, spleen, lymph nodes)
  • Bone marrow aspirate
  • Synovial biopsy
  • Synovial fluid samples - joint fluid aspirates (use same containers for synovial fluid crystal detection - please note that samples for crystal detection should reach the lab as soon as possible).

Which Container does it go in?

Image of sterile sample containersImage of sterile sample containers

A variety of sterile universal containers can be used for collection of sterile samples. the white capped 30mL container shown on the left is most reliable because of its tight closing lid.


  • Transport the sample to the laboratory as quickly as possible.
  • Note: The recovery of anaerobes is compromised if transport time exceeds 3 hours.
  • Do not refrigerate the sample.

Page Reviewed: 07/10/15 | Updated by: Kevin Roberts