Legionella pneumophila DFA
Ordering Recommendation

Use for the rapid identification of L. pneumophila; sensitivity is dependent on patient population and specimen type. Molecular testing is generally preferred; refer to Legionella Species by Qualitative PCR (2010125).

Direct Fluorescent Antibody Stain
Within 24 hours
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Pericardial fluid, respiratory, or tissue specimens. 
Specimen Preparation
Fluid: Prepare two duplicate slides. OR transfer 1 mL fluid to a sterile container.
Tissue: Transfer tissue to a sterile container and place on gauze moistened with sterile non-bacteriostatic saline to prevent drying. 
Storage/Transport Temperature
Refrigerated. OR frozen if transport occurs more than 48 hours after collection. 
Unacceptable Conditions
Non-respiratory specimens. Specimens in preservatives or viral transport medium. 
Specimen source preferred. 
Fluid or Tissue: Ambient: 12 hours; Refrigerated: 48 hours; Frozen: 1 week
Slides: Ambient: 1 week; Refrigerated: 1 week; Frozen: 1 week 
Reference Interval
Interpretive Data

A negative stain result does not exclude the possibility of infection. False-negative results may occur due to sampling errors or a low number of organisms in the specimen. DFA is not recommended for diagnosing Legionella pneumophila-caused infections. For diagnosing Legionella pneumophila-caused infections, refer to Legionella Species, Culture (ARUP test code 0060113), Legionella Species by Qualitative PCR (ARUP test code 2010125) for amplified DNA testing of respiratory specimens, or Legionella pneumophila Antigen, Urine (ARUP test code 0070322) for urine specimens.
Component Test Code*Component Chart NameLOINC
2004599Legionella pneumophila DFA Source31208-2
2004600Legionella pneumophila DFA Result588-4
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • L. pneumophilia DFA
  • Legionella Smear, DFA