Practical 2: RhD Grouping Flashcards
What does RhD positive mean
Red cell bear the D antigen
What does RhD negative mean
Red cells don’t bear the D antigen
What must also be ran when running an RhD test?
RhD control must be ran
What are the two anti-D anti-sera called?
RUM-1
MS201
What should the results of the RhD control be?
It should always be negative
For how long should you incubate your tubes?
5 to 10 minutes
How should you centrifuge your tubes
centrifuge at 2000rpm for 30seconds (P2)
What is the other method other than tubes of grouping patients?
Gel/column agglutination technique
What gel is used for ABO grouping
BioRad ABO and Rh D grouping gel cards
When should you not use a gel?
(4)
If they show signs of drying
If they have bubbles
If the seals are damaged
If there are drops of gel or supernatant in the upper part of the microtubes or on the underside of the aluminium foil
How much rbcs should you add to the ID card
10ul (in notes)
50ul (in practice)
How much plasma and reagent cells should you add to the ID card
50ul of reagent cells
50ul plasma
For how long should you centrifuge the cards?
10 minutes
What is the reverse grouping cards called?
ID-DiaCell ABO
What is a positive ID card result
Agglutination of cells which form a red line on the surface of the gel or agglutinates dispersed in the gel
What is a negative ID card result
Compact button of cells on the bottom of the tube
What does it mean if you have a button and a red line in your ID card?
Mixed field
What causes a mixed field?
Bone marrow transplant
Blood transfusion
What are the seven controls for the ABO + RhD test
(7)
Colour of anti-sera
Anti-AB
2 anti-Ds against different D epitopes
RhD control
Reverse group
Daily controls (to see if reagents and anti-sera are working)
Daily controls (double check cell type)
What is the principle of gel technology
(4)
Sephadex gel matrix acts as a sieve
Large agglutinates remain on or near the top of the gel interface
Smaller agglutinates pass partway through gel depending on their size
Un-agglutinated cells pass to base of microtube to form a button
What is different about how we use gels in the college versus the lab
Lab will use a foil piercing device and a dilution pipette
- don’t have to dilute rbcs by hand
Give two brands of gels used in Ireland
BioRad
Ortho Biovue
How does BioRad differ from Ortho Biovue
BioRad uses gel
Ortho Biovue uses glass beads
What must you be careful to do when pipetting into the gels
Disperse liquid on side of reaction chamber -> not directly onto gel or into the air gap
