Blood bank Unit 1 test
Equal expression of two different inherited genes as in most blood group systems
Codominant genes
Hemolysis was observed at room temperature when testing a patient's serum with reagent red cells used for screening. When this test was repeated using the patient's plasma, no hemolysis was observed. What was the most likely explanation for the different reactions?
Complement activation was inhibited by calcium in the plasma sample.
Which of the following clinical applications applies to molecular testing for blood group antigens?
Confirm the D type of blood donors, identify fetus at risk of HDFN, predict the phenotype of a patient with autoimmune hemolytic anemia (All of the above)
Accuracy
Degree to which a measurement represents the true value
Incubation step is not necessary
Direct antiglobulin test
tests for certain clinical conditions such as hemolytic disease of the newborn and autoimmune hemolytic anemia
Direct antiglobulin test
OSHA
Ensures safe and healthful working conditions
Validation
Establishing that a specific process produces an expected result
Competency assessment
Evaluation of an employee's ability to perform a specific skill
What portion of the antibody molecule binds to receptors on macrophages and assists in the removal of antibody bound to red cells?
Fc fragment
Which of the following organizations are involved in the regulation of blood banks?
Food and Drug Administration
Which of the following is true regarding good manufacturing processes?
GMPs are legal requirements established by the FDA
The linked HLA genes on each chromosome are inherited as a
Haplotype
When two genes are close together on the same chromosome and are inherited as a group or bundle
Haplotypes
Of the following markers used to test for paternity, which marker provides the most useful statistical value?
Human leukocyte antigen typing
Viable region of an immunoglobulin
Idiotype
Found in secretions such as breast milk
IgA
Associated with allergic reactions and mast cell activation
IgE
Able to cross the placenta
IgG
Has the highest serum concentration
IgG
What immunoglobulin class is capable of crossing the placenta?
IgG
What immunoglobulin class reacts best by antiglobulin testing?
IgG
Which immunoglobulin class is impacted by the zeta potential in a hemagglutination test?
IgG
Associated with immediate spin in vitro reactions
IgM
Associated with intravascular cell destruction
IgM
Efficient in activation of the complement cascade
IgM
Has the highest number of antigen binding sites
IgM
Select the immunoglobulin class produced first in the primary immune response
IgM
What immunoglobulin class reacts best at room temperature at immediate spin?
IgM
Why is polyethylene glycol reagent added to the screen or panel?
Increase the avidity of IgG antibodies
In order to enhance the reaction of an antibody in vitro, it may be necessary to adjust which of the following?
Increase the incubation time in the incubator
In a routine audit of a facilities blood collection area, the quality assurance department found that the blood bags used on that particular day had expired. What is the appropriate course of action?
Initiate a root cause analysis and quarantine the blood collected in the expired bags. Notify the FDA since the expired bags were distributed.
Root cause analysis
Investigation and identification of of the factors that contributed to an error
One of the two types of light chains
Kappa
CDC
Makes recommendations to OSHA regarding the prevention of disease transmissions
Preventive maintenance
Maximizes the duration of equipment and increases the reliability of the equipment
A laboratory technologist decided she would like to bring her lab coat home for laundering because it had too many wrinkles when it was returned by the laboratory's laundry service. Is this practice acceptable?
No, because the laboratory is a biosafety level 2, and lab coats may not be removed
A technologist in training noticed that the person training her had not recorded the results of a test. To be helpful, she carefully recorded the results she saw at a later time, using the technologist's initials. Is this an acceptable procedure?
No; she should have brought the error to the technologist's attention.
The children of a group AB mother and group B father could phenotype as all fo the following except
O
Reagent to identify the specificity of a red cell antibody
Panel cells
When testing for the A antigen in a patient, what would you use to perform the test?
Patient's red cells and anti-A
All of the following are responsibilities of the quality assurance department of a blood bank except
Performing quality control
What reagent contains antibodies to multiple antigenic epitopes?
Polyclonal-based
Technique used to replicate a specific DNA sequence
Polymerase chain reaction
Which red cells are used to screen for antibodies in donor samples?
Pooled screening cells
In the PCR reaction, what is the term for the short pieces of single stranded DNA that are complementary and mark the sequence to amplified?
Primers
Short segment of DNA with a known sequence that can be labeled with a marker
Probe
Calibration
Process of standardizing an instrument against a known value
AABB
Professional organization that accredits blood banks and transfusion services
CAP
Provides peer reviewed accreditation for hospital labs
Recall
Removal of products from the market that might compromise the safety of the recipient
The antiglobulin test was performed using tube technology. A button of cells was observed at the bottom of the microtube following centrifugation. How do you interpret the result?
Result is a negative reaction
Reagent to detect the presence of red cell antibodies
Screening cells
Which of the following terms provides evidence for reagent red cell deterioration?
Spontaneous agglutination, significant hemolysis, loss of agglutination strength over time (all of the above)
Change control
System to plan and implement changes to prevent problems
Quality control
Testing to determine the accuracy and precision of reagents and equipment
Proficiency test
The CAP survey is an example
Why is incubation omitted in the direct antihuman globulin test?
The antigen-antibody complex has already formed in vivo
Several units were released to a hospital by mistake before all viral marker testing was completed. What is the appropriate course of action?
The error is reportable, and the Food and Drug Administration must be contacted. Call the hospital and request a quarantine of the remaining products in inventory.
A facility does not validate a refrigerator before use. What is a potential outcome?
The facility is in violation of current good manufacturing practices and could be cited by the Food and Drug Administration.
When using the Hardy-Weinberg equation to calculate genetic frequencies, which of the following must be true?
The population statistics must be large. Mutations cannot occur. Mating must be random (All of the above)
Which of the following statements is true regarding high protein anti D reagents
They have been largely replaced with low protein monoclonal reagents. They contain approximately 20% bovine albumin. They may increase the possibility of a false-positive reaction, requiring the use of a control. (All of the above)
How would you interpret the results if both the anti D and Rh control were 2+ agglutination reactions?
Unable to determine without further testing
Which of the following is an example of an unacceptable record keeping procedure?
Using dittos in columns to save time
Rouleaux is a false-positive reaction that would not likely be observed during which of the following tests
Weak D test
A father carries the Xga blood group trait and passes it on to all of his daughters but to none of his sons. What type of inheritance pattern does this demonstrate?
X-linked dominant
In the solid phase red cell adherence test, how does a negative test appear?
a button of cells on the bottom of the well
Employee training takes place
after hiring and following implementation of new procedures
Personal protective equipment includes:
all of the above
Which of the following is not an advantage of using a monoclonal antibody over a polyclonal antibody?
all variations of the antigen can be detected
Amplified target sequences of DNA produced by polymerase chain reaction
amplicon
What specificities does polyspecific antihuman globulin contain?
anti-IgG and anti-C3d
Which of the following is responsible for the activation of the classic pathway of complement?
antibody bound to antigen
In a serologic test, the term prozone is also known as:
antibody excess
Select the test that uses IgG-sensitized red cells (check cells).
antiglobulin test
An antigen that originates from the individual is termed
autologous
How are most blood group systems inherited?
autosomal codominant
Detects IgG or complement-coated red cells
both the direct and indirect antiglobulin test
Requires washing the cells several times before the addition of antihuman globulin reagent
both the direct and indirect antiglobulin test
What is the purpose of adding antibody sensitized red cells following the antiglobulin test?
check that the wash procedure was sufficient to remove unbound antibodies
Select the portion of the antibody molecule that imparts the antibody's unique class function.
constant region of heavy chain
Plans that provide the framework for establishing quality assurance in an organization are:
continuous quality improvement plan.
Select the substance that regulates the activity of other cells by binding to specific receptors
cytokines
FDA
ensures safety and efficacy of biologics, drugs and devices
Part of the antigen that the immunoglobulin binds to
epitope
A technologist added 4 drops of a 5% red cell suspension instead of the required 1 drop to a hemagglutination test. What is the potential consequence to the test results?
false negative
What is the potential effect in a tube agglutination test if a red cell suspension with a concentration greater than 5% is used?
false negatives
Select the method that uses a dextran-acrylamide matrix.
gel technology
What part of the immunoglobulin molecule distinguishes the isotype?
heavy chain
The standard operating procedure is a document that
helps achieve consistency of results
A person whose red cells type as M+N+ with antisera would be
heterozygote
Imparts flexibility to the immunoglobulin molecule
hinge region
In safety training, employees must become familiar with all of the following except
how to perform cardiopulmonary resuscitation on a donor or other employee.
The binding of two complementary pairs of DNA
hybridization
Monoclonal antibodies are prepared
in vitro
The type of immunoglobulins determined by the heavy chain
isotype
All of the following are true regarding competency testing except
it is required only if the technologist has no experience.
Reagent derived from plants used to distinguish group A1 from group A2 red cells
lectins
The gel technology method uses a concentration of red cells that is:
lower than tube techniques
When does crossing over occur?
meiosis
When an individual is group A, which of the following genetic terms applies?
phenotype
Reagent antibodies prepared from human sources are:
polyclonal in specificity
Having two or more alleles at a given gene locus
polymorphic
In relationship testing, a direct exclusion is established when a genetic marker is
present in the child but absent in both the mother and alleged father.
Unacceptable quality control results for the antiglobulin test performed in test tubes may be noticed if:
preventive maintenance has not been performed on the cell washer, the technologist performing the test was never trained, the reagents used were improperly stored (All of the above)
Marks the sequence to be amplified during PCR
primer
Where are product limitations and technical considerations for each reagent located
product insert
What biological molecules are considered the most immunogenic?
proteins
When a gene product is expressed only when it is inherited by both parents
recessive
Which of the following will cause an antigen to elicit a greater immune response?
size greater than 10,000 daltons
Extravascular destruction of blood cells occurs in the
spleen
Audit
systematic evaluations to determine whether procedures are being followed
Blood irradiators require all of the following safety procedures except:
that the user have a degree in radiology
Biosafety levels determine:
the degree of risk for certain areas of a health care facility to exposure to infectious diseases.
Solid-phase red cell adherence used for antibody detection has an advantage over tube testing because:
the endpoint is more clearly defined
If two traits occur higher in a population together than each occurs separately, they may be linked. What does this fact suggest?
the genes are close together on the same chromosome
Which of the following statements is true regarding IgG sensitized red cells?
they must be used to confirm a negative antiglobulin tube test
Mitosis results in
two cells with the same number of chromosomes as the parent cell
Select the region of the antibody molecule responsible for imparting unique antibody specificity.
variable region
If anti-M was reacted with red cells that are M+N+, how would they compare with red cells that are M+N-?
weaker
How is RNA different from DNA?
1) has ribose not deoxyribose 2) contains Uracil (U) instead of Thymine 3) usually single stranded (All of the above)
What is the approximate probability of finding a compatible unit of blood for a D positive patient with antibodies for C, E and K if the frequency of C is 70%, E is 30% and K is 10%?
2 out of 10 units
Following centrifugation of the gel card, red cells are observed to be evenly dispersed throughout one of the microtubes. This reaction could be graded as a:
2+
What temp is used for incubation in the indirect antihuman globulin test?
37 Celsius
After adding antigen and antibody to a test tube, one large agglutinate was observed. How should this reaction be graded?
4+
In a random population 16% of the population is homozygous for a particular trait. What percentage of the same population is heterozygous for that particular trait?
48%
What is an advantage of Nucleic Acid Testing for viral marker testing?
A small amount of of DNA/RNA can be detected
What is the meaning of the term autosomal?
A trait that is not carried on the sex chromosomes
Reagent used in the identification of ABO antibodies
A1 and B cells
Reagent used to determine the ABO antigenic compositions of a patients red cells
ABO antisera
In a family study, all four siblings in the family had a different blood type: A, B, O, and AB. What is the most likely genotypes of the parents?
AO and BO
An antibody identified in the transfusion service appeared to be reacting stronger following the second exposure to an antigen from a transfusion. The most likely explanation of this observation is
Affinity maturation of the immunoglobulin molecule, anamnestic response and isotype switching (all of the above)
Select the term that describes cells or from a genetically different individual within the same species.
Allogenic
A gene that does not express a detectable product
Amorphic genes
Which of the following red cell antigens do proteolytic enzymes destroy?
Antigens Fya and Fyb in the Duffy system
Select the cell involved in humoral immunity.
B lymphocytes
At what point in the employment process should safety training take place?
Before independent work is permitted and annually thereafter
What process is described by opsonization?
Binding to cells or antigens
In the complement cascade, lysis of the target cell is mediated by which of the following components?
C5 to C9
