Note: None of the methods listed below are widely available.
Immunohistochemical staining(IHC) and Indirect immunofluorescent staining (IIF)
Available as staining techniques that use an antibody specific to Naegleria fowleri. A microscopic examination follows. These techniques are primarily used to identify N. fowleri in formalin-fixed tissue but can be used to make an identification in CSF as well.
Serology
Indirect immunofluorescent antibody (IFA) is used to measure serum antibody titers. However, this method is not useful because most patients die before any immune response is mounted.
Polymerase chain reaction (PCR)
Another laboratory tool that may be used for the identification of N. fowleri is the multiplex PCR. This reaction can amplify and identify the DNA of free-living amoebae in CSF in approximately five hours.
Culture
A sample of CSF is inoculated onto a petri dish containing 1.5% non-nutrient agar which has been seeded with an unspecified strain of E. coli. The plates are incubated at 37° C and examined for up to one week. Growth of N. fowleri can be confirmed by tracks made by the amoebae as they move across the agar eating the bacteria. Note: A negative culture does not rule out the presence of free-living amoebae.
7. Centers for Disease Control and Prevention (CDC). Image, "N. fowleri culture". Image in the public domain; referenced by author.
