Immunofluorescence

Last updated: Thursday, 11, March, 2004
Item Process
Specimen

Lesion or organ biopsy eg, skin, kidney, lung; must be fresh, unfixed and delivered immediately to the laboratory. 

Immunofluorescence transport medium can be used if the laboratory is distant or delivery is delayed. 

Consult laboratory staff prior to obtaining and sending the specimen to ensure optimal sampling and processing conditions. 

In special circumstances, antigen retrieval can be used for immunofluorescence of fixed tissue. 

The results of this are, however, often unsatisfactory as there are problems with reliability, sensitivity and altered staining patterns.

Method

Direct immunofluorescence.

Application

Detection of immunoglobulin and complement deposition, especially in renal and skin biopsies.  Detection of viral or bacterial antigens eg, cytomegalovirus, mycobacteria, legionella. 

Immunofluorescence has now been surpassed by immunohistochemistry for T and B cell identification, detection of tumour related antigens and tissue localisation of hormones and enzymes.

Interpretation

Positive staining indicates the presence of the antigen. 

The pattern and localisation of staining is an aid in the diagnosis of some bullous and inflammatory skin diseases and immune complex and antibody-mediated renal diseases. 

Detection of viral and bacterial antigens confirms the presence of a specific infection.

Reference

Elias JM. Immunohistopathology: A Practical Approach to Diagnosis. 2nd ed. ASCP 2003.

Shi S-R et al. Antigen Retrieval Techniques. Eaton, Natick 2000.