COMPLEMENT FIXATION

This is a set of protein thermolabile found in the serum that propose that material of binding antibody to antigen complex. These complement was known to be fixed for example

Ag + Ab  →  Ag – Ab complex

Now the complex will undergo reaction as illustrated bellow

Ag – Ab complex + C →   Ag – Ab – C complex

The complex poses enzyme material which in the present of antibody – antigen on the surface of the cell, it confront the cell membrane which result to lysis in the reaction. The material poses the lead to lysis is gotten from the complement fixation test and that may be employed in the examination of exact antibodies or antigen for example when antibody is present, these can be explained by much inclution of it corresponding antigen these followed indirectly by complement. When antibody is present it will stick with the antibody – antigen reaction complex i.e the fixing of the complement that take place in the absent of the antibody thereby complement fixation did not shown. But in the case of adding red cell indicator that go along with antibody – antigen complex on their surfaces the free complement will project the cell lysis. But in a situation where by the antibody  subjected for testing were present, then the lysis of the cell will be absent because complement fixation is present in the antibody subject, in these case it lead to absent of lysis, but if the test antibody is present then lysis of the cell must surely take place because of the free complement activity. It is one way forward case for adaptation of the explained step above foe detecting antigen using exactly antibody in the reaction.