Whenever possible, fluid, pus or tissue samples should be submitted in preference to swabs. This will enable the full range of appropriate tests to be performed, including viral testing and mycobacterial microscopy and culture. Samples should be submitted in dry sterile, screw cap universal containers.
 
Central nervous system (CNS) specimens
Suggested volumes for routine, fungal and mycobacterial cultures are 1, 2 and 2ml respectively. In patients suffering from bacterial meningitis, blood cultures as well as nose and pharyngeal bacterial transport medium (BTM) swabs should be collected in all cases - even when cerebrospinal fluid is collected prior to antibiotic administration.  In suspected meningococcal infection, a blood sample should be submitted for meningococcal PCR - a minimum of 2.5mls of blood in EDTA is required from patients of all ages.  Acute and convalescent serum samples may enable a retrospective diagnosis.  In cases where viral meningitis is suspected, pharyngeal swabs for viral PCR.