Rh Factor VS RhD Factor

Bottom Line:

They are the same thing! D is the most common antigen in the Rh blood group system so people keep things simple by just saying “Rh” instead of RhD. Note that RhD can also be denoted as RhO (sometimes using a subscript letter O or number 0). So Rh, RhD, RhO, RhoD, RhO or Rh0 can all refer to the D antigen of the Rh blood group system.

Memory Aids:

When in doubt, it’s the Rh D antigen. Continue reading “Rh Factor VS RhD Factor”

Direct Coombs Test VS Indirect Coombs Test

Bottom Line:

With the direct Coombs test you just add the anti-Ig antibodies (Coombs reagent) to your test solution and watch for agglutination. With the indirect Coombs test you have to add RBCs first, then you add the anti-Ig antibodies, and then watch for agglutination. So there is an extra step with the indirect Coombs test.

Direct Coombs is also called DAT (direct antiglobulin test).

Memory Aids:

Indirect has an extra step. Direct lets you go directly to the result. Continue reading “Direct Coombs Test VS Indirect Coombs Test”