While it has been said that PCR is likely to replace DFA as the test of choice, accessibility to and cost of the technique may limit the number of laboratories that are able to implement the process. Still, the advantage of DFA staining relative to other diagnostic methods, including PCR, is the provision of a rapid result and lower overall cost. The laboratory diagnosis of pertussis remains problematic, and polyclonal DFA reagents for its detection have brought into question the utility of DFA. However, the integration of a commercially available monoclonal DFA reagent, in combination with the development and standardization of existing procedures, should provide clinicians with an improved method for the diagnosis and epidemiology of pertussis.