However if there is antibody in the patients serum there will be no antigen

However if there is antibody in the patients serum

This preview shows page 8 - 15 out of 19 pages.

the indicator system. However, if there is antibody in the patient’s serum, there will be no antigen-antibody complex, and therefore, complement will be present free or unfixed in the mixture. This unfixed complement will now react with the antibody-coated sheep red blood cells to bring about their lysis. Thus, no lysis of sheep red blood cells (positive CFT) indicates the presence of antibody in the presence of antibody in the test serum, while lysis of sheep red blood cells (Negative CFT) indicates the absence of antibody in the serum.
Image of page 8
Image of page 9
Positive Test At 37°C Complement gets fixed Step 1: Antigen + Antibody + Complement (from serum) 1 Hour At 37°C Step 2: Fixed Complement complex + Haemolytic system 1 Hour No Haemolysis (Test Positive)
Image of page 10
Negative Test Step 1: At 37°C Antigen + Antibody absent + Complement Complement not fixed 1 Hour At 37°C Step 2: Free Complement + Haemolytic system 1 Hour Haemolysis (Test Negative)
Image of page 11
Results and Interpretations: No haemolysis is considered as a positive test . haemolysis of erythrocytes indicative of a negative test . 1 2 3 4 A B Microtiter plate showing Haemolysis (Well A3, A4 and B4) and No Haemolysis (Well)
Image of page 12
Serum Neutralization Test
Image of page 13
Principle of serum neutralization test Neutralization : A procedure in which biological activity of toxin or a living organism is inhibited, usually by a specific neutralizing antibody. In vitro neutralization test: The serum sample or solution of antibody to be tested is diluted and mixed with a viral suspension or toxin. This is incubated to allow the antibody to react with the virus or toxin.
Image of page 14
Image of page 15

You've reached the end of your free preview.

Want to read all 19 pages?

  • Fall '15
  • MrRosdi
  • antigen-antibody complex

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes