Serology

Some agglutination / Serological test :

VDRL
Widal
Weil-Felix reaction
Rheumatoid Arthritis (RA / RF Test)
Anti-Streptolysin-O(ASO)
C-reactive protein(CRP)
Blood grouping

VDRL : Venereal Disease Research Laboratory.

Indication : To diagnose Syphilis & Gonorrhoea.

Widal test :

Indication : To diagnosis of Typhoid & Paratyphoid fever.

Interpretation of Widal Test Result :

TO titre	TH Titre	Interpretation
1 : 80	1 : 40	Normal
1 : 160 or more	1 : 80	Typhoid fever
1 : 160 or more	1 : 160 or more	Typhoid fever
1 : 80	1 : 160 or more	Anamnestic reaction

Weil-Felix reaction :

Indication : Rickettsial Fever

Rheumatoid Arthritis (RA / RF Test) :

Indication : Rheumatoid Arthritis.

ASO titre test:

Indication : Rheumatic fever.

C-reactive protein(CRP) :

Indication : Non-specific marker of inflammation such as infections, autoimmune diseases, and cancer.

Titre : It is the highest dilation of the serum giving a positive reaction.

Antigen : Any substance which binds with antibody is called antigen.It may be immunogenic or non-immunogenic.

Antibody : An antibody is a type of globulin (immunoglobulin) produced in response to an antigen with which it reacts specifically.

Antigen antibody reaction :

It is the combination of an antigen with its specific antibody.

Importance of antigen antibody reaction :

Diagnosis of disease.
To assess the progress of specific treatment.
To detect the antibody titre after immunisation.
To identify organism.

Triple Antigen Test :
Widal
Typhoid : TO, TH
Paratyphoid A : AO, AH
Paratyphoid B : BO, BH

Weil-Felix reaction
Rickettsial Fever : OX2, OXK, OX19

Brucellosis
Brucella Abortus : BA
Brucella Melitensis : BM

ICT : Immunochromatographic Test.

Indications of ICT :

ICT for Hepatitis B (HBsAg)
ICT for Pregnancy (Urine)
ICT for HCV, HIV, Dengue (NS1, IgG, IgM).
ICT for Syphilis
ICT for Malaria

CFT : Complement fixation test.

Indication of CFT :

CFT for Filaria
CFT for syphilis and Lyme disease.
CFT for Herpes Simplex Virus (HSV), Cytomegalovirus (CMV), and Epstein-Barr virus.

Sensitivity :

Sensitivity is calculated as the number of true positives divided by the total number of people with the disease. For example, if a test has a sensitivity of 80%, then 80 out of 100 people with the disease will test positive.

Specificity :

Specificity is calculated as the number of true negatives divided by the total number of people without the disease. For example, if a test has a specificity of 90%, then 90 out of 100 people without the disease will test negative.