When a screening test such as the rosette test indicates a significant FMH, a quantitative test is required to determine the dose of RhIg required. Tests include
- Kleihauer-Betke acid elution test (KB test);
- Flow cytometry;
- Other techniques that are less commonly used, eg, fluorescence microscopy and enzyme-linked antiglobulin test.
The KB and flow cytometry methods are briefly reviewed on the following pages.