Serological reactions

Prof. Dr.

AbD El-GAwAD M. HAsHEM

Complement Fixation reaction

Anti -omplementary

Control opaque

+ vetiter=40

+ veall opaque (except C)

- veall clear

Contaminant similar to Ab is present

Ab is specific Ab is specfic and in high conc.

Ab is not specific

Indicator system: sensitized sheep RBCs (RBCS + sp. haemolysin)

Test system: patient’s serum + external complement + specific Ag

* precaution ! heat the patient’s serum at 56°C for 30 min. to inactivate naturall y present complement

screeningsyphilisUsed for

Prof. Dr.

AbD El-GAwAD M. HAsHEM

Complement fixation test (CFT) -ve All tubes show hemolysis

Complement fixation test (CFT) +ve All tubes show no hemolysis except control

Complement fixation test (CFT) Titer 2First two tubes show no hemolysis

Complement fixation test(CFT) anticomplement All tubes show no hemolysis

Prof. Dr.

AbD El-GAwAD M. HAsHEM

Widal testWidal test Direct Cell agglutinationType of

reactionO somatic Ag of S. typiH Flagellar Ag of S. typiAH Flagellar Ag of paratyphi ABH flagellar Ag of paratyphi B

Reagent

Cellular Ags of SalmonellaFrom attenuated or killed bacteria

Clinical Significance

Detection of serum Ab against S. typhi or paratyphiCause of enteric fever -present from 2nd week

(Use)

Prof. Dr.

AbD El-GAwAD M. HAsHEM

ASO test (Anti Streptolysin O )

(1) –ve (4) +ve

Passive latex agglutinationType of reaction

Titer = reciprocal of last+ve if > 200 ∴ abnormal

Result

Suspension of polystyrene latex coated with stabilized streptolysin O enz.

Reagent

Detection of ASO in patient’s serum- Strept.is present associated with rheumatic fever

Clinical Significance (Use)

Prof. Dr.

AbD El-GAwAD M. HAsHEM

RPR test (Rapid Plasma Reagin)

Carbon flocculation testType of reaction

Cardiolipin Suspended on microparticulate charcoal to enhance visual diff. Bet + ve , -ve

Reagent

Ab: is called regainAg: “cardiolipin” heterophile Ag (a lipid from beef heart) +ve screening Of syphilis infection

Clinical Significance (Use)

Prof. Dr.

AbD El-GAwAD M. HAsHEM

Ouchterlony

a) Titer 4 or more b)Titer 20

a b

Gel precipitationType of reaction

Titer = reciprocal of last dilution showing line of precipitation

Result

Soluble antigen or antibody .Reagent

Detection of soluble antigen or antibody

Clinical Significance (Use)

Prof. Dr.

AbD El-GAwAD M. HAsHEM

ESR (Erythrocyte sedimentation rate)Westergren tube

Normal After 1 hour♂ 15 mm♀20 mm

result

ESR- infection - inflammation

(as rheumatoid & rheumatic fever)- Anaemia- Pregnancy ESR- Polycythemia

Clinical significance and uses

Prof. Dr.

AbD El-GAwAD M. HAsHEM