Lab 10 blood bank .iq

Lab 10

blood bank

Antibody Titer Test

Definition

The antibody titer is a test that detects the presence and measures the amount of antibodies within a person's blood. The amount and diversity of antibodies correlates to the strength of the body's immune response.

The antibody titer is a measurement of how much antibody an organism has produced that recognizes a particular epitope, expressed as the inverse of the greatest dilution that still gives a positive result. For example, the indirect Coombs test detects the presence of anti-Rh antibodies in a pregnant woman's blood serum a patient might be reported to have an "indirect Coombs titer" of 16. This means that the patient's serum gives a positive indirect Coombs test at any dilution down to 1/16 (1 part serum to 15 parts diluent).At greater dilutions the indirect Coombs test is negative. If a few weeks later the same patient had an indirect Coombs titer of 32 (1/32 dilution which is 1 part serum to 31 parts diluent), this would mean that she was making more antiRh antibody, since it took a greater dilution to abolish the positive test. Many traditional serological tests such as hemagglutination or complement fixation employ this principle. Such tests can typically be read visually, which makes them fast and cost-effective in a "low-tech" environment. The interpretation of serological titers is guided by reference values that are specific for the antigen or antibody in question; a titer of 1:32 may be below the cut-off for one test but above for another.

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blood bank

Uses of Antibody Titer Test

An antibody titer is prescribed to investigate problems regarding:

frequent bacterial or viral infections

low levels of white blood cells

liver disease

flu-like symptoms

suspected viral disease

suspected autoimmune disorder

suspected parasite infection

to determine if a repeat vaccination or booster is needed

Indirect Coomb's Titer

Reagents

1- bovine albumin

2- AHG

3- Normal saline

4- O cells suspension

5- patient's serum.

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blood bank

Equipment & instruments

1- 10 test tubes & rack

2- Micropipette

3- Centrifuge

4- Incubator

5- Microscope

Procedure

1- take 10 test tube(label the tubes from 1 to 10 ) & add 0.5 ml of normal saline in each tube

2- In the first tube add 0.5 ml of patient serum mixed well and gently.

3- Transfer 0.5ml of serum to the first tube and from the first tube to the second tube, and from second tube to the third until tube number 9,then discard 0.5 ml of this tube....tube number 10 is a control.

Lab 10

blood bank

4- Add 50 micron of (O) cell suspension for each tube.

5-Add 2 drop of bovine albumin for each tube.

6- Incubate at 37c for 30 minute.

7- Add 4ml of normal saline for each tube and centrifuge at 2000 for 1 minute (repeat it 3 time ) .

8- Add 2 drop of AHG for each tube .

9- Examine each tube for agglutination the result will be in the last tube agglutination occur in it.

Titer: 160

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