Test Catalog

Test ID: CCOC    
Coccidioides Antibody, Complement Fixation and Immunodiffusion, Spinal Fluid

Method Description Describes how the test is performed and provides a method-specific reference

Complement Fixation:

The immune response of a person to an infection frequently begins with the formation of specific antibody that is capable of combining in vitro with homologous antigen and complement (C'). The complement fixation (CF) test is a 2-stage test based on the ability of antigen-antibody complexes to bind C'. In the first stage, antigen and antibody combine and fix C'. The second stage is an indicator system in which sheep erythrocytes, sensitized by rabbit anti-sheep red cell antibody (hemolysin), are used to demonstrate the presence of unfixed C'. If the patient's serum contains C'-fixing antibody that reacts with the specific antigen (a positive reaction), C' will be fixed and excess C' will not be available to react with and lyse the sensitized sheep erythrocytes. If no antigen-antibody reaction occurs (a negative reaction), C' will be available to lyse the sheep erythrocytes. The CF titer is determined by the greatest dilution of serum (antibody) in which the sheep erythrocytes are not lysed.



Immunodiffusion (ID) is a qualitative test employed for the detection of precipitating antibodies present in the CSF. Soluble antigens of the fungus are placed in wells of an agarose gel filled Petri dish and the patient's CSF and a control (positive) CSF are placed in adjoining wells. If present, specific precipitate antibody will form precipitin lines between the wells. Their comparison to the control CSF establishes the results. When performing the ID test, only precipitin bands of identity with the reference bands are significant.(Kaufman L, Kovacs JA, Reiss E: Immunomycology. In: Rose NR, de Macario EC, Folds JD, et al, eds. Manual of Clinical Laboratory Immunology. 5th ed. ASM Press, 1997:591-593; Ramanan P, Wengenack NL, Theel ES: Laboratory diagnosis for fungal infections. A review of current and future diagnostic assays. Clin Chest Med. 2017 Sep;38[3]:535-554)

PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.

Monday; 6 a.m.

Tuesday through Friday; 9:30 a.m.

Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.

3 days

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Clinic Laboratories until the release of the test result

6 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

14 days

Performing Laboratory Location Indicates the location of the laboratory that performs the test