PowerPoint Contents
Authors: Kristina M. Obom, Gary Brooker, Maria A. DeBernardi, Patrick J. Cummings
Citation: Kristina M. Obom, Gary Brooker, Maria A. DeBernardi, Patrick J. Cummings. 2009. Indirect immunofluorescence for detection of measles antibody.
Publication Date : February 2009
Introduction
The figure shows a positive indirect fluorescent antibody serological test for measles virus immunoglobulin G (IgG) antibody. Individuals who are seropositive for measles have antibody that binds to infected Vero cells forming a viral antigen-antibody complex. The antigen-antibody complex is visualized by the addition of an antihuman antibody tagged with fluorescein isothiocyanate (IgG-FITC), which binds to the antigen-antibody complex and fluoresces apple green. All cells are counterstained with Evans blue which fluoresces orange red. Measles virus induces the fusion of infected cells resulting in a large multinucleated cell (syncytia). Note syncytia formation in the center of the photograph. Also note that the viral antigen is found only in the cytoplasm of infected cells. The image was captured using a Pathway Bioimager 855 (BD Biosciences) with a 20x objective.
Methods
Measles virus infected cells that were inactivated and fixed to slides were provided by Hemagen Corporation, Columbia, MD (Virgo Measles IFA Kit, 903105). Cells were incubated with diluted human serum for 30 minutes at 37oC, washed in phosphate buffered saline for 15 minutes to remove unbound immunoglobulin and then incubated for 30 minutes at 37oC with antihuman IgG-FITC and Evans blue dye counterstain. The slides were washed again for 15 minutes in phosphate buffered saline to remove unbound label and counterstain and imaged using a Pathway Bioimager 855.
Discussion
Measles is an ancient human infection first described by Rhazes in the 10th century (1). While a very effective live attenuated vaccine developed by Enders and colleagues (2) was licensed in 1963, measles remains a significant source of morbidity and mortality worldwide. The World Health Organization estimates there were 242,000 deaths due to measles in 2006, the majority of deaths occurred in children (3).
Indirect immunofluorescence is a standard diagnostic method for identifying infection and assessing immune status for a variety of viruses including herpes simplex virus, cytomegalovirus, rubella, Epstein-Barr virus, and others.
References
1. Abu Becr, M. A. 1748. Discourse on the smallpox and measles (R. Mead, translator). J. Brindley, London, England.
2. Enders, J. F., S. L. Katz, M. V. Milovanovic, and A. Holloway. 1960. Studies on an attenuated measles virus vaccine. I. Development and preparations of the vaccine: techniques for assay of effects of vaccination. N Engl J Med. 263 : 153–159.
3. World Health Organization. 2008. Measles fact sheet. http://www.who.int/mediacentre/factsheets/fs286/en/.
Contact Information
ASM Education, education@asmusa.org