CFT Full Form – Complement Fixation Test
CFT Full Form – Crystal Field Theory
CFT Full Form – Cubic Foot
Complement Fixation Test
The complete fixation test (CFT) is used to detect the presence of specific antibodies in the patient’s serum. CFT is mainly used to diagnose infections. It was introduced by Wasserman in 1909. In the beginning, it was extensively used in syphilis serology.
procedure Of CFT
- The first step is to heat the serum at 56°C to destroy patient’s complement.
- A measured amount of complement and antigen are then added to the serum. If there is presence of antibody in the serum, the complement is fixed due to the formation of Ag-Ab complex. If no antibody is present then the complement remains free.
- To determine whether the complement has been fixed, sheep RBCs and antibodies against sheep RBCs are added.
Advantages of Complement Fixation Test
- Ability to screen against a large number of viral and bacterial infections at the same time.
Disadvantages of Complement Fixation Test
- Not sensitive – cannot be used for immunity screening
- Time consuming and labor intensive
- Often non-specific e.g. cross-reactivity between HSV and VZV
Crystal Field Theory
The cubic foot is a unit of volume, used in the United States, and partially in Canada, and the United Kingdom. It is defined as the volume of a cube with sides of one foot (0.3048 m) in length. Its volume is 28.3168 liters or about 1⁄35 of a cubic meter.