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LATEX TEST FOR ANTI STREPTOLYSIN "O" (ASO)


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Principle

Antistreptolysin 'O' (ASO) test kit is based on the following principle Polystyrene latex particles are coated with purified and stabilized Streptolysin O (antigen), which reacts with its corresponding Antistreptolysin O (antibody). in the test sample resulting in the agglutination of latex particles. Results are expressed in IU/mL of anti-Streptolysin O (ASO) based on the WHO International Standard.

Specimen: Serum or plasma.

Requirement

  1. ASO Latex Reagent.
  2. Positive Control Serum.
  3. Negative Control Serum.
  4. Glass Slide.
  5. Disposable Applicator Sticks.
  6. Disposable Plastic Droppers.
  7. Rubber Teats.

Procedure

A. QUALITATIVE SLIDE TEST

Bring test sera and reagents to room temperature (+15 °C to +30 °C) before testing and mix gently prior to use.

with the help of disposable plastic dropper place one drop of undiluted Test serum within the circled area on the special slide provided in the kit.

Add one drop of well mixed ASO Latex Reagent. 

Mix the reagent and serum using the applicator stick and spread within The entire circle of the glass slide.  5) Slowly rock the slide and observe for macroscopic agglutination. Do not observe for longer than 2 minutes.

B. SEMI QUANTITATIVE SLIDE TEST

1) All samples giving positive results in the qualitative test should be tested by Semi-quantitative test or Hemolysin titration test.

2)Prepare dilutions of the serum sample with normal saline as suggested in The following table Serum Dilution Corresponding IU/mL


3)With the help of disposable plastic dropper, dispense one drop of diluted serum into one of the circled area on the special slide provided.

4) Add one drop of well mixed ASO Latex Reagent.


Observation Table

A. Qualitative test


B. Semi-Quantitative Test


Conclusion :

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Clinical Significance

Most of the strains of streptococci which are pathogenic for human beings belong to Group A. All such organisms produce an exotoxin known as Streptolysin 'O' (SLO) besides other toxins and enzymes.When infected with infection, a patient will produce an antibody, anti-Streptolysin 'O' (ASO) that is detectable in serum.Increased ASO titers may be associated with Rheumatic fever and  Glomerulonephritis.An elevated ASO titer of more than 200 IU/mL indicates past or present acute streptococcal infection.

The titer of ASO should be observed repeatedly over a time of 4 to 6 weeks to follow the course of an injection.ASO Antistreptolysin 'O' Latex Test Kit provides a simple screening method of detecting an elevated ASO titer and obviates the necessity of performing a cumbersome and time hemolytic inhibition test in all patients.

Reference

KIT USED  - ARKRAY HEALTHCARE PVT. LTD. 

ASO ANTISTREPTOLYSIN 'O' LATEX TEST KIT 

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