Immunofluorescence (IF) techniques utilize antibodies labeled with fluorescent dyes to detect specific antigens, with common dyes including fluorescein isothiocyanate (FITC) and rhodamine. There are two main methods of IF: direct immunofluorescence, which uses a single antibody conjugated to a fluorophore, and indirect immunofluorescence, which employs a primary unconjugated antibody and a fluorophore-conjugated secondary antibody. This technique has applications in clinical and research settings, such as diagnosing skin diseases and detecting antibodies in conditions like toxoplasmosis and related infections.

1. Immunofluorescence
Lecturer: S. Pordel
M.Sc. of Immunology

2. Introduction
 Immunofluorescence (IF) or cell imaging techniques
rely on the use of antibodies to label a specific target antigen
with a fluorescent dye (also called fluorophores or
fluorochromes) such as fluorescein isothiocyanate (FITC).
 Fluorochromes are dyes which have the ability to absorb
the short wavelength UV radiation and emit light of longer
wavelength fluorescence ( visible green light).
 Examples : FITC, Rhodamine

3. There are two ways of doing IF staining:
 Direct immunofluorescence
 Indirect immunofluorescence
 Direct immunofluorescence: Direct IF uses a single
antibody directed against the target of interest. The
primary antibody is directly conjugated to a fluorophore.

4. What is direct immunofluorescence?
Its applications are Clinical and Research.
Direct immunofluorescence (DIF) is a technique used in the laboratory to
diagnose diseases of the skin, kidney, and other organ systems.
DIF involves the application of antibody–fluorophore conjugate molecules to
samples of patient tissue obtained from biopsies

6.  Indirect
immunofluorescence:
Indirect IF uses two
antibodies. The primary
antibody is unconjugated
and a fluorophore-
conjugated secondary
antibody directed against
the primary antibody is
used for detection.

7. Toxoplasmosis:

8. We want to find anti-Toxoplasma antibodies in the patients
So
What should be our method?
1. Direct immunofluorescence
2. Indirect immunofluorescence

10. Continue…

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 About 95% of those
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