Which reagent is used for testing weak D by incubating patient’s red cells?

The correct choice employs the use of anti-D serum followed by washing and antiglobulin serum for testing weak D. This method is specifically designed to detect the presence of weak D antigens on red blood cells, which are commonly encountered in patients with weak D phenotypes.

When conducting this test, anti-D serum is first applied to the patient’s red blood cells. If the red cells have weak D antigens, the anti-D will bind to these antigens during the incubation phase. Following this, the washing step helps to remove any unbound antibodies. By adding antiglobulin serum afterward, the test can detect any bound antibodies that signal a positive reaction for the presence of weak D. The antiglobulin serum reacts with the IgG antibodies, which allows for agglutination to occur if weak D is present.

The effectiveness of this method relies on each of these steps. For instance, dilutions of anti-D serum may not provide the specificity required to test weak D effectively as it does not ensure the optimal interaction necessary for accurate results. Similarly, using just antiglobulin serum without the initial anti-D step would not appropriately identify weak D antigens, as the test would lack the necessary initial binding step.

In conclusion, the process