The Widal test detects antibodies in the blood that are produced in response to Salmonella Typhi and Paratyphi bacteria, which cause typhoid fever. The test involves mixing the patient's serum with antigens (O, H, AH, BH) from the bacteria. If antibodies are present, they will cause the antigens to clump or agglutinate. A positive result indicates the patient likely has or previously had typhoid fever. The Widal test was developed by Georges Fernand Widal and is an agglutination test that helps diagnose typhoid fever.

1. (WIDAL TEST)
Presented by:-
Mr. ASHISH

2. SPECIFIC OBJECTIVE
 DEFINITION OF WIDAL TEST
 TYPE OF WIDAL TEST

3. DEFINITION OF WIDAL TEST
 Widal test is a type of agglutination test which is used to
typhoid fever ( enteric fever)
 The widal test detects antibodies against O( somatic surface
antigen) or H (flagella antigen of the suspected organism
)antigens.
 Type of technique is use direct agglutination .
 Widal test was firstly discovered by Georges fernand widal.

4. SALMONELLA ANTIGEN
They are two type of salmonella bacteria.
Salmonella typhi
(s.paratyphi)
Antigen O (TO)
Antigen H (TH)
Salmonella typhi
(s.typhi)
Antigen AH
Antigen BH

5. PROCEDURE OF WIDAL TEST
1.SLID AGGLUTINATION TEST:
1.REQUIREMENTS:-
Widal
Dropper
Mixture
2.SAMPLE-patient serum
3. REAGENT-
O-antigen AH-antigen
H-antigen BH-antigen

6. PRICIPAL OF WIDAL TEST
 Widal test is type of agglutination test.
 Patient serum mix antigen.
 If any antibody present in patient serum then agglutination
occur .
 If antibody not present then agglutination not occur.
 Test positive-(agglutination present)
 Test negative-(agglutination absent)

7. PROCEDURE OF WIDAL TEST
 Take clean and dry widal slide.
 Now add 1-1 drop serum in each circle.
 Mix all antigen in each circle O,H,AH,BH.
 Mix of thoroughly with aid of the applicator stick and rotate
the slide gently.
 Now see the agglutination.
RESULT- agglutination was observed with in a 1min
positive& negative

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13. PROCEDURE OF DILUTION TEST
TUBE
 For the preparation of dilution add 0.9 normal saline and
0.1ml patient serum in first tube and other tube add 0.5 ml
normal saline.

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21. THANK YOU