2.1.1 Fluid/semi-fluid specimens

Most fluid specimens are inoculated by transferring a 5-20 µl aliquot into liquid or solid media. However, some procedures require larger volumes of inoculum, for example, when inoculating different types of media in parallel to enable the isolation of a range of pathogens with different nutritional requirements (see Section 4.3). Hence, specimens consisting of only a few drops of fluid are inadequate and at least 1 mL should be submitted.

Swabs absorb a limited amount of fluid and should only be used when fluids cannot be collected in containers, for example, genital secretions or when collection in a container is likely to introduce contamination, such as a fistulous duct draining to the skin.