The document discusses the serological diagnosis of viral infections, detailing methods for identifying antibodies and antigens in patient samples. It highlights the historical development of serological methods, including the invention of the ELISA technique and the discovery of monoclonal antibodies. The document also outlines various types of serological reactions and their applications in diagnosing viral infections, along with the advantages and limitations of techniques like ELISA and Western blot.

1. SEROLOGICAL
DIAGNOSIS OF VIRAL
INFECTIONS:
POSSIBILITIES OF
SEROLOGICAL DIAGNOSIS
TYPES OF SEROLOGICAL
REACTIONS
Presentation on

2. Presented By
Sulove Kumar Ghosh
Student ID: MS-190807
Plant Pathology
Agrotechnology Discipline
Khulna University

3. Introduction
Serological methods are diagnostic methods
that are used to identify antibodies and
antigens in patients sample which is serum and
plasma.
A serological diagnosis is prepared by
detecting the rising titres of antibody or
antigens
By serological methods most of the common
viral infections are diagonized.

4. Historical Development
1798 - First demonstration of vaccination smallpox
vaccination (Edward Jenner)
1890 - Demonstration of antibody activity against
diphtheria and tetanus toxins.
1900 - Antibody formation theory (Paul Ehrlich)
1938 - Antigen-Antibody binding hypothesis (John
Marrack)
1948 - antibody production in plasma B cells

5. Historical Development
1959 -1962 - Discovery of antibody structure
Enzyme Linked ImmunoSorbent Assay {ELISA}
1971 - Peter Perlmann and Eva Engvall at
Stockholm University invented ELISA
1975 - Generation of the first monoclonal
antibodies (George Kohler and Cesar Milstein)
1978- Used ELISA for plant virus identification
1985- Identification of immunoglobulin gens

6. SEROLOGICAL REACTIONSSEROLOGICAL REACTIONS
Ag-Ab reactions used for the detection
of unknown Ag or Ab, in vitro
In virology:
Viral (direct) diagnosis:
- detection of viral antigens
Serological (indirect) diagnosis:
- detection of specific antiviral antibodies

7.  Qualitative detection of total specific
antiviral antibodies
 Quantification of total specific antiviral
antibodies (titer of Abs)
1/2 1/4 1/8 1/16 1/32 1/64
POSSIBILITIES OF SEROLOGICAL
DIAGNOSIS
POSSIBILITIES OF SEROLOGICAL
DIAGNOSIS

8. Detection of Ab classes (qualitative and
quantitative)
POSSIBILITIES OF SEROLOGICAL
DIAGNOSIS
POSSIBILITIES OF SEROLOGICAL
DIAGNOSIS

9. Detection of Ab synthetized to each viral
protein (Ag) of specific molecular weight –
serological profile
POSSIBILITIES OF SEROLOGICAL
DIAGNOSIS
POSSIBILITIES OF SEROLOGICAL
DIAGNOSIS

10.  Determination of specific antibody avidity
POSSIBILITIES OF SEROLOGICAL
DIAGNOSIS
POSSIBILITIES OF SEROLOGICAL
DIAGNOSIS

11. ClassicalModern
Types of serological reactionsTypes of serological reactions
I. – detection of Ab that block biological functions of the virus
Neutralization test
Haemagglutination Inhibition Test
II. – based on biological activity of Abs in complex with Ags
Immunoagglutination
Complement Fixation Test (CFT)
III. – based on application of labeled antibodies
EIA (ELISA)
Immunofluorescence
RIA
IV. – determination of serological profile
Western blot

12. based on application of
labeled antibodies
ELISA – Enzyme Linked ImmunoSorbent Assay
Microtiter Plate(96)

13. Different types of ELISA

14. ELISA

15. Advantages of ELISA
Reagents are relatively cheap & have a long
shelf life
ELISA is highly specific and sensitive
No radiation hazards occur during labelling or
disposal of waste.
Easy to perform and quick procedures
Equipment can be inexpensive and widely
available.
ELISA can be used to a variety of infections.

16. Disadvantages of ELISA
Measurement of enzyme activity can be more complex
than measurement of activity of some type of
radioisotopes.
Enzyme activity may be affected by plasma
constituents.
Kits are commercially available, but not cheap
Very specific to a particular antigen. Won’trecognize
any other antigen
False positives/negatives possible, especially with
mutated/altered antigen

17. Limitations
•Results may not be absolute
•Antibody must be available
•Concentration may be unclear

18. determination of
serological profile
Western blot as serological reaction: confirmation test
(HIV)
Serological profile – presence of Ab specific for
different viral Ag

19. Western Blot for HIV
HIV-1 Western Blot
• Lane1: Positive Control
• Lane 2: Negative Control
• Sample A: Negative
• Sample B: Indeterminate
• Sample C: Positive
At least 1 Ab for products of all 3 major genes (3)
(CDC) Two Ab for any of the 3 major Ag:
p24, gp41, gp120/160 (2)
3 genes:
-GAG
-POL
-ENV
POSITIVE

20. THANKS TO ALL