Serology Flashcards
Objective
Give agglutination reaction grade
0
negative, no agglutination
Cells remove from cell button as smoke or cloud
Objective
Give agglutination reaction grade
3+
Many large agglutinates in clear background. As cell button is shaken, agglutinates remove easily in large chunks
Objective
Give agglutination reaction grade
1+
Very small agglutinates. Come off as cookie bites from button
Objective
Give agglutination reaction grade
4+
Solid agglutination
Cells stick together into one solid chunk floating in liquid background
Objective
Give agglutination reaction grade
2+
Many small agglutinates in clear background.
Agglutinates appear to crumble off into solution
Objective
How do you interpret results of serologic reactivity in determining the presence or absence of Ag on patient RBCs or Ab in patient’s plasma?
- Positive or Negative
- Incompatible or Compatible
Word of the day
Monoclonal
Antibodies usually mouse-sourced that come from single clone of hybridoma cells
How do you get monoclonal antibodies?
- Immunize mouse with human specific Ag
- Remove spleen cells and combine B cells with human myeloma cells
- Hybridoma cells screened for antibody
- One clone selected and propagated in tissue culture
Advantages of mAbs?
Single ant
Single Ab secreted is available forever, highly specific, and pure
Disadvantages of mAbs?
- Only detects single epitope so can miss variables in population
- Initially takes longer to produce
Incidence
% frequency of Ag present in population in population frequency chart
High incidence
More than 90%
Low incidence
Less than 10%
Ag phenotypic testing
Serology where you use anti-sera to ID RBC Ag
T/F
A person makes an Ab for an Ag they do have on RBCs
False
People make Ab for Ag they don’t have on RBCs. Antithetical Ag does not matter
What population frequency of Ag indicates compatible blood?
100%
Antibody ID method
Use known cells to ID unknown Ab
What is the #1 cause of a transfusion reaction?
Data entry error
Document control regulations
- All test results must be recorded as they are tested, don’t wait to record even if you don’t think what you see is right
- All data entry needs 2nd tech to review
- Consult procedures before discarding. Strict guidelines for how long docs are kept
- All original docs must be legible and in permanent pen. Single line cross-out errors followed by date and initials accepted
Sample labels
- 2 pt identifiers
- date/time of collection
- collector name
- secondary ID method if necessary (armband or 2nd specimen)
When do you reject a hemolyzed sample?
Moderate hemolysis
hemolysis >= 200 mg/dl
How do you maintain sample integrity?
- EDTA preferred, centrifuged to separate from plasma
- No gel separator or hemolysis
- Appropriate labeling
- Enough volume to perform testing
Causes of hemolysis?
- Already occurring in pt or due to blood draw
- Hemolysis can indicate positive reaction in blood bank testing (but it’s bad)
Patient history to look for (compare records to current results and investigate/resolve discrepancies before issuing unit for transfusion)
- ABO/Rh type
- Difficult blood typing
- Clinically significant Ab
- Adverse events to transfusion
- Special transfusion requirements