Biopsies or cultures of a person's tick wound (eschar) are used to diagnose ATBF. However, this requires special culture media and can only be done by a laboratory with biohazard protection.[18] There are more specialized laboratory tests available that use quantitative polymerase chain reactions (qPCR), but can only be done by laboratories with special equipment.[18] Immunofluorescence assays can also be used, but are hard to interpret because of cross-reactions with other rickettsiae bacteria.[8]