Histoplasma Antigen for Immunodiffusion (ID) Test System Immy 0.1ml

The CFT fungal antigens and positive controls are used to detect antibodies in patient serum by the complement fixation (CF) procedure to aid in the
diagnosis of four specific fungal diseases: Histoplasmosis, Blastomycosis, Coccidioidomycosis, and sera should be tested with each of the antigens, since there is some overlap in antigenicity between the various fungi and the symptoms of the
diseases are very similar. Higher CF titres are usually observed on patient sera when they are tested against the same antigen as the aetiologic agent of
their infection.
The test is based on the Laboratory Branch Complement Fixation (LBCF) Test Procedure (as published by the Centers for Disease Control, Atlanta,
GA)5. The principal of the CF test is that antibodies present in patient sera, when mixed with their appropriate antigens will “fix” or take-up complement
(a component of fresh serum). This “fixation” of complement is determined by adding an assay system consisting of sheep red blood cells (SRBC)
sensitized with anti-SRBC (hemolysin) and measuring the percentage of lysis of the SRBC (complement is required for lysis). If complement has been
“fixed” the indicator SRBC’s will not be lysed.
The CF test involves two basic principles:
1.) Complement (C’) is irreversibly reacted (fixed) by certain classes of antibody-antigen complexes (certain classes of antibodies do not fix complement).
The degree of fixation is governed by the relative concentration of antibody or antigen.
2) The lysis of SRBC that have been sensitized with hemolysin is dependent upon complement being present.
The CF test (Serum + Antigen + C’ — incubate — + sensitized SRBC) is interpreted as follows:
Antibody present = NO HAEMOLYSIS
Antibody absent = HAEMOLYSIS
FOR RESEARCH USE ONLY