MLT GlobeIndirect antiglobulin test (IAT)
Blood Bank · also called Indirect Coombs test, ICT, Antenatal antibody titer
What it measures
Detects free antibodies in plasma that can coat red cells, using test cells and anti-human globulin. Used in antibody screening, crossmatching and to follow antibody levels in pregnancy.
Specimen and preparation
- Specimen: Serum or plasma (EDTA)
- Tube: Pink top
- Preparation: In pregnancy, test at booking and at 28 weeks in RhD-negative women, or as advised.
Reference range
| Group | Range |
|---|---|
| All | Negative |
Reference ranges differ between laboratories, methods and populations. Always use the range printed on your own lab report.
Causes of high values
- Red cell alloimmunization from pregnancy or transfusion
- Risk of hemolytic disease of the fetus and newborn
- Warm autoimmune hemolytic anemia
- Recent anti-D prophylaxis (low titer)
Method
Incubation of plasma with red cells at 37 °C followed by anti-human globulin; gel or tube technique; titration for titers
Good to know
Anti-D titers of 16 or more (or a critical titer set by the lab) usually prompt fetal monitoring with Doppler studies.
Related tests
📱 Practise with a timer, track your score and earn certificates in the free MLT Globe app – Google Play or practise online.