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”

Exudate VS Transudate

Bottom Line:

Fluid that collects in extracellular, extravascular spaces can be either exudative or transudative. Exudative fluid arises from inflammatory processes that make vessel walls more permeable to both fluid and proteins which allow them to exit the vessels and collect in the extravascular spaces. Transudative fluid exits the vessels due to a pressure differential between the intra and extravascular space (either hydrostatic or oncotic), but typically does not contain proteins since they are too large to squeeze out of the vessels. A fluid sample can be tested according to Light’s criteria to determine if it is exudative or transudative.

Memory Aids:

Exudates are from Enflammation (inflammation)

Light’s criteria – protein 5, LDH 6

(fluid protein:serum protein >0.5, fluid LDH:serum LDH>0.6) Continue reading “Exudate VS Transudate”

Creatinine VS Creatine

Bottom Line:

CreaTINE is converted in the body to phosphocreatine which is used to make ATP in high energy requiring tissues like the brain and skeletal muscle. CreaTININE is the breakdown product of creatine and is used as a biomarker of kidney function.

Memory Aids:

CreaTINE turns into creaTININE. Continue reading “Creatinine VS Creatine”

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”

Hepatitis B: HBsAg VS Anti-HBs

Bottom Line:

HBsAg (Hepatitis B surface antigen) is the one you are most likely to see on routine screening bloodwork for Hep B. If it is positive the person is likely actively infected with Hep B either chronically or acutely.

Memory Aids:

Surface Antigen is the one you want to remember. Continue reading “Hepatitis B: HBsAg VS Anti-HBs”