Term
| What information must appear on the label of the specimen? |
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Definition
| full name, ID number, date & time drawn, initials or ID of phlebotomist |
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Term
| Blood bank testing should be done on samples no older than? |
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Definition
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Term
| A sample used for crossmatch should be kept in the blood bank refrigerator for a minimum of? |
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Definition
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Term
| What is the difference between serum and plasma? |
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Definition
Serum- no anticoagulant, clot + serum, functional complement
Plasma- anticoagulant, cells + plasma, no functional complement |
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Term
| Why is serum preferred over plasma? |
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Definition
| Some abs hemolyze rbcs in the presence of functional complement; without complement these abs may be missed |
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Term
| When might a sample clot? |
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Definition
Anticoagulant therapy
Arterial line draw
Clotting disorder |
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Term
| What should be added on the non-clotting sample if the patient is on heparin or Coumadin? |
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Definition
Heparin- 3 drops protamine sulfate
Coumadin- 2-4 drops reconstituted thrombin |
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Term
| What is meant by washing cells? |
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Definition
"wash" with saline
Removes unwanted plasma proteins, Abs, & dead cells |
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Term
| Why is it important to use a cell suspension that ranges from 2 - 5%? |
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Definition
Provides optimum ag concentration
Zone of equivalence
Lattice formation |
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Term
| If your cell suspension is less than 2%, how can a proper suspension be prepared? |
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Definition
recentrifuge
Decant saline
resuspend cells --> 2-5% |
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Term
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Definition
Clear pink to red tinge in the supernatant
Indicates a positive rxn
Found in presence of functional complement & ab-ag rxn |
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Term
| Mixed field agglutination |
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Definition
| two different red cell populations in one sample |
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Term
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Definition
Tests a patients rbcs with Anti-A, Anti-B, & Anti-A,B
Determines blood type |
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Term
|
Definition
Tests a patients sample of serum with known A and B rbcs
Must agree with forward group to determine blood type |
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Term
| What is an ABO discrepancy? |
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Definition
| When the forward and reverse group do NOT agree |
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Term
| What should be done when a discrepancy occurs? |
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Definition
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Term
| What is the source of the reagent anti-A,B? |
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Definition
| Human O donors or murine clonal sources |
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Term
| What is the importance of the reagent anti-A,B? |
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Definition
Verify group O individuals
Verify dicrepancies |
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Term
| Why is the test tube method preferred over the slide method? |
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Definition
Slide method is less sensitive
Can only be used in forward grouping
Biohazard |
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Term
| If an AO and BO mate, what are possible genotypes? |
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Definition
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Term
| Why A2 cells used by some hospitals in reverse grouping? |
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Definition
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Term
| Saliva test with no agglutination after O indicator cells are added? Secretor or non-secretor? |
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Definition
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Term
| Individual secretes H substance only in saliva. What is his ABO blood group? |
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Definition
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Term
| An individual whose rbcs agglutinate with anti-D rapid tube test after immediate spin would be called? |
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Definition
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Term
| An individual whose rbcs did NOT agglutinate with anti-D antiserum after immediate spin, but DID agglutinate after a 37-degree incubation and an indirect antiglubulin test would be called |
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Definition
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Term
| What is meant by a high protein medium? |
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Definition
| Bovine albumin and/or colloid polymer such as PVP, dextran, or Ficoll |
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Term
| What is meant by a low protein medium? |
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Definition
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Term
| What is one disadvantage of using an anti-D antiserum suspended in a high protein medium? |
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Definition
| RBCs can agglutinate spontaneously |
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Term
| What is in the Rh control reagent? |
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Definition
| Contains all of the same ingredients as the anti-D reagent, EXCEPT for the anti-D ab |
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Term
| Why must a Rh control tube be ran when a high protein anti-D antiserum is used? |
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Definition
| Check for spontaneous agglutination |
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Term
| Why isn't the saline tube test used routinely? |
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Definition
|
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Term
| When is the saline tube test used? |
|
Definition
Rh control tube shows agglutination
DAT is positive |
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Term
| What is used for the "control tube" for a low protein clonal anti-D reagent? |
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Definition
| Any negative reaction in the ABO forward grouping |
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Term
| What is used for the "control tube" for an individual who is Group AB? |
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Definition
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|
Term
| What should be done if the Rh control tube is positive? |
|
Definition
INVALID RESULTS--> DO NOT REPORT
Repeat Rh typing
Do a DAT on patients RBCs |
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Term
| Why must one wash many times when performing a IAT? |
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Definition
| Remove any unbound anti-D ab |
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Term
| What are Coombs control cells? |
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Definition
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|
Term
| Why are Coombs control cells used? |
|
Definition
Check any negative result
Agglutination verifies results |
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Term
| Is it possible for an Rh-negative, weak D negative recipient to develop anti-D when transfused with weak D positive red cells? |
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Definition
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Term
| Is it possible for a weak d recipient to develop anti-D when transfused with Rh positive rbcs? |
|
Definition
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|
Term
| What is meant by an ABO discrepancy? |
|
Definition
| Interpretation of the forward and reverse group does NOT agree |
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|
Term
| 3 major groups of discrepancies? |
|
Definition
1. Additional rxns
2. Missing rxns
3. Extra rxns |
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Term
| What errors might result from the cell suspension being too heavy or light? |
|
Definition
Improper ratio of cells to serum
Pro-zone or post-zone |
|
|
Term
| More than one red cell population may exist because... |
|
Definition
recent transfusion
chimerism
bone marrow transplant |
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|
Term
|
Definition
modified ag on the membranes of blood group A1 rbcs that agglutinates
Due to enzymatic modification of the normal A1 into a B-like ag
Caused by bacteria associated with GI pathogenicity |
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Term
| Why can A and/or B be weakly expressed? |
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Definition
Allelic variants (weak subgroups)
Disease: leukemia or Hodgkins lymphoma |
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Term
| If the reverse grouping tubes are incubated at 4-degrees, why must an auto control be ran parallel? |
|
Definition
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|
Term
|
Definition
| stacks or aggregates of RBCs |
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|
Term
| What conditions does rouleaux cause? |
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Definition
| Causes additional reactions in the reverse grouping |
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Term
| What ages are considered extremes of age? |
|
Definition
Newborns (6 months and younger)
Unhealthy elderly |
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Term
| What can extremes of age cause? |
|
Definition
Missing rxns
Reverse group should NEVER be done on a newborn |
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Term
| What is the most likely explanation for a positive Rh control? |
|
Definition
Patients rbcs coated with ab in vivo
Cause spontaneous agglutination |
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Term
| How do we show that a blood group A individual has the A2 phenotype? |
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Definition
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Term
| Why is anti-A,B used when an individual groups as O? |
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Definition
| Verify and subgroups of O |
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|
Term
| How can secretor studies be used to resolve ABO discrepancies? |
|
Definition
Identify subgroups of A or B ags.
Secretors inherit Se allele & express soluble forms of H ags in secretions |
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Term
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Definition
| the observed expression of the 5 antigens on the rbc surface |
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|
Term
|
Definition
| the inherited arrangement of the 3 allelic pairs of genes on homologous chromosomes |
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|
Term
| Is phenotyping and genotyping preformed routinely? |
|
Definition
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|
Term
| When might phenotype and genotype be preformed? |
|
Definition
1. Confirm ID of alloantibody
2. Suggest what Rh alloantibodies are likely to develop on individual
3. Paternity testing |
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|
Term
| What types of reagents are available for Rh phenotyping? |
|
Definition
1. Low protein reagents (human IgM ab, human/mouse heterohybridoma IgM abO
2. High protein reagents (IgG ab) |
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Term
| Why are heterozygous, rather than homozygous red cells preferred as a positive control? |
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Definition
Sensitivity- avoid false negatives
Specificity- avoid false positive |
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|
Term
| What is the most common genotype for a person possessing the D antigen? |
|
Definition
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|
Term
| What is the most common geneotype for a person lacking the D antigen? |
|
Definition
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|
Term
| Why are there many more possible genotypes for the Rh positive phenotypes than for the Rh negative phenotypes? |
|
Definition
There is no little d
Dd and DD is dominant D and establishes a higher number of genotypes |
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