Monday, October 12, 2009

ASOT


Streptolysin-O is a type of exotoxins produced by β-haemolytic group A Streptococcus. People infected with β-haemolytic group A Streptococcus will produce specific antibodies against the streptococcal exotoxins. Antistreptolysin-O Test (ASOT) is a rapid latex particle agglutination test that uses latex reagent, a suspension of uniform sized polystyrene latex particles coated with streptolysin-O, which allows visual observation of the antigen-antibody reaction. Presence of antistreptolysin-O in the serum will result in agglutination of the latex particles.

ASOT is commonly ordered by doctors whom patient is suspected of having Group A Streptococcus infection. Procedure for ASOT is as followed.

1. A drop of positive control was dispensed onto the 1st test area.
2. A drop of negative control was dispensed onto the 2nd test area.
3. A drop of sample was dispensed onto the 3rd test area using micropipette.
4. A drop of latex reagent was added to the 3 test areas.
5. Sample and reagent were mixed thoroughly using wooden sticks.
6. Test card was placed on electronic rotator for 2 minutes at 100 ± 2 rpm.
7. Test results was observed and recorded.

A negative ASOT result does not rule out the possibility of patient having Group A Streptococcus infection. If patient is still suspected of having the infection, a second blood sample should be taken for the test four weeks later from the previous ASOT test day.

Hui Juan
0702012F
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6 comments:

  1. MedScientists of Grp 6October 13, 2009 at 6:18 PM

    HELLO 'the composer' =D

    I just wonder if there is any sign or symptom that cause the doctor to suspsect that the patients may have Group A Strep infection yah?

    And what are some common diseases that the patients may suffer from if they are infected with Group A Strep?

    Thankz in advance ^^
    Vo Thu Hong Anh [Jess]
    0705364H

    ReplyDelete
  2. BordetellasOctober 15, 2009 at 1:40 AM

    hi hui juan!
    what kind of blood sample are usually taken for this test?

    nyzah
    0702888I

    ReplyDelete
  3. BordetellasOctober 16, 2009 at 5:50 AM

    hello vanessaa!

    why a negative ASOT result does not rule out the possibility of patient having Group A Streptococcus infection?

    siti shahimah
    0702717J
    :)

    ReplyDelete
  4. emadtechsNovember 19, 2009 at 5:14 PM

    hey Nyzah,
    we usually use serum for this test, but if the patient do not have enough serum, plasma from EDTA tubes can also be use.

    hi Siti,
    a negative result does not rule out the possibility of patient having Group A Streptococcus infection because it can be a recent infection, hence antibody titre in the blood might not be detectable in the early stage. So if the patient is still suspected of Group A Streptococcus infection due to the clinical symptoms presented, a second specimen should be sent and tested after 3 weeks.

    hello Jess,
    the symptoms of Group A Streptococcus infection includes sore throat, severe pain and swelling,fever, confusion, sudden onset of generalized or localized severe pain, often in arms or legs and dizziness. Influenza-like symptoms may also occur, but some infected patients can be asymptomatic.

    Common disease associated with Group A Streptococcal infection are necrotizing fasciitis, a disease where the muscles, fats and skin tissues are destroyed at a rapid speed and Streptococcal Toxic Shock Syndrome (STTS) whereby a sudden drop in blood pressure results in organ failure occur.

    Hui Juan
    TG01

    ReplyDelete
  5. accumaximumFebruary 2, 2011 at 4:59 AM

    Micropipette is used formally. Since laboratory personnel must deal with installing and ejecting such a large number of tips.

    Micropipette

    ReplyDelete
  6. amoebaOctober 29, 2018 at 6:18 AM

    Read on cryptococcus latex test principle and procedure
    https://mltgeeks.com/latex-cryptococcus-antigen-test-crag-principle-and-result-interpretation/

    ReplyDelete

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