RH TYPING PROCEDURE:
- The slide method is easy to perform.
- This method is described as diagramatically.
Rh typing slide method
Rh- typing reading
False-positive result in slide method:In the case of drying of the slide, it may mimic agglutination.
Rule out the presence of microclots and these may mimic agglutination.
Inadequate amount of the anticoagulant.
False-negative result in slide method:Saline suspension of the RBCs may react poorly or give a weak reaction.
In the case of anemic patients, there may be fewer RBCs to be tested.
If you read the result in less than 2 minutes may give false result in case of weak RBCs.
If you use the wrong reagents.
- The tube method is more accurate than the slide method.
This method is described as diagramatically.
Rh typing tube method procedure
False-positive result in tube method is:If you keep for a long time serum and the RBCs, then because of the high protein medium, you may see false agglutination which basically is rouleux formation.
The anti-Rho (D) serum used may contain other antibodies with different specificity.
If there are contaminating antibodies with the specificity other than indicated in the literature.
If there are polyagglutinable RBCs that may agglutinate by any serum protein reagents.
In case if the patient has abnormal proteins in the serum.
False-negative result in tube method:In the case of improper reagents used in the test.
If serum and the cells left for a long time will give rise to rouleux formation which may be taken as agglutination.
RBCs with variant antigens e.g Cw, ces, may fail to react with standard reagents.