Difference between revisions of "Complement Fixation"
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+ | |linkpage =Immunology - WikiBlood | ||
+ | |linktext =IMMUNOLOGY | ||
+ | |sublink1 =Immunological testing - WikiBlood | ||
+ | |subtext1 =IMMUNOLOGICAL TESTING | ||
+ | |pagetype =Blood | ||
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Complement fixation is a test that exploits the fact that antibody-antigen complexes are able | Complement fixation is a test that exploits the fact that antibody-antigen complexes are able | ||
to activate the complement system, using the mechanism to show the presence of a specific antibody in a serum sample. | to activate the complement system, using the mechanism to show the presence of a specific antibody in a serum sample. | ||
− | ==Method== | + | ===Method=== |
A mixture of antibody, complement and antigen is incubated and an indicator system (normally antibody-coated sheep red blood cells) is added. | A mixture of antibody, complement and antigen is incubated and an indicator system (normally antibody-coated sheep red blood cells) is added. | ||
*As the complement reaction with the immune complex produces no visible result, sheep red blood cells are coated with anti-sheep red blood cell antibody. The complement in the mixture will react with this antibody and lyse the cells. | *As the complement reaction with the immune complex produces no visible result, sheep red blood cells are coated with anti-sheep red blood cell antibody. The complement in the mixture will react with this antibody and lyse the cells. | ||
An indication of a positive test is the absence of lysis of the red blood cells, as the complement has already been used up by the antigen-antibody system. Controls are included to ensure that none of the reagents have taken up the complement non-specifically (e.g. contaminated serum) | An indication of a positive test is the absence of lysis of the red blood cells, as the complement has already been used up by the antigen-antibody system. Controls are included to ensure that none of the reagents have taken up the complement non-specifically (e.g. contaminated serum) | ||
− | ==Applications== | + | ===Applications=== |
*'''Wasserman reaction'''- used in the diagnosis of syphilis, the test consists of a mixture of Wasserman antigen, dilutions of the patients serum and complement (normally sourced from guinea pigs). | *'''Wasserman reaction'''- used in the diagnosis of syphilis, the test consists of a mixture of Wasserman antigen, dilutions of the patients serum and complement (normally sourced from guinea pigs). | ||
*Virus detection- tissue samples are innoculated with blood or tissue samples from a patient and tested using complement fixation | *Virus detection- tissue samples are innoculated with blood or tissue samples from a patient and tested using complement fixation | ||
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Revision as of 12:40, 12 September 2008
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Complement fixation is a test that exploits the fact that antibody-antigen complexes are able
to activate the complement system, using the mechanism to show the presence of a specific antibody in a serum sample.
Method
A mixture of antibody, complement and antigen is incubated and an indicator system (normally antibody-coated sheep red blood cells) is added.
- As the complement reaction with the immune complex produces no visible result, sheep red blood cells are coated with anti-sheep red blood cell antibody. The complement in the mixture will react with this antibody and lyse the cells.
An indication of a positive test is the absence of lysis of the red blood cells, as the complement has already been used up by the antigen-antibody system. Controls are included to ensure that none of the reagents have taken up the complement non-specifically (e.g. contaminated serum)
Applications
- Wasserman reaction- used in the diagnosis of syphilis, the test consists of a mixture of Wasserman antigen, dilutions of the patients serum and complement (normally sourced from guinea pigs).
- Virus detection- tissue samples are innoculated with blood or tissue samples from a patient and tested using complement fixation