Blood Bank Makeup Exam Part 2 Flashcards
A patient has anti-P1 that reacts only with ficin treated cells. What should be done to find four units of compatible red blood cells?
Test donor cells with compared anti-P1 until 4 units are found; then crossmatched at 37 degrees to AHG
No crossmatching beyond the immediate spin phase is necessary; therefore, find four units of the patient’s ABO/Rh type. Any units found compatible at the immediate spin phase can be transfused
Crossmatch ABO/Rh compatible cells at 37 C degrees to AHG. Any that are compatible can be transfused
Neutralize the serum with hydatid cyst fluid and perform crossmatches at 37 degrees to AHG. Anything compatible can be transfused
Crossmatch ABO/Rh compatible cells at 37 C degrees to AHG. Any that are compatible can be transfused
Which two blood group systems are similar in that the antigens are highly antigenic and any antibodies against these antigens are clinically significant, yet finding compatible red blood cells lacking the antigens is not difficult?
P and I blood group systems
Rh and K blood group antigens
Kidd and Duffy blood group systems
Lutheran and Lewis blood group systems
Rh and K blood group antigens
What is the most likely explanation when screen cells, panel cells, the auto control and all crossmatches are positive at 37 degrees, but negative after the addition of antihuman globulin?
A warm autoantibody
A mixture of warm autoantibodies and alloantibodies
Rouleaux
An alloantibody to a high incidence antigen
Rouleaux
Why is anti-IgG needed to detect IgG sensitized cells?
The IgG molecule attracts more than one cell and anti-IgG creates a spatially accurate distance between cells
The IgG molecule coating cells cannot span the distance between sensitized cells; therefore, anti-IgG links the Fc portions of the bound IgG molecules so that a lattice is formed, and agglutination is detected
The anti-IgG is specific for the variable region of all IgG antibodies; therefore, it is the ideal antibody to detect any specificity
The anti-IgG molecule can span the distance between cells and can attach to the antigen on red blood cells, pulling them together and causing visualization of agglutination
The IgG molecule coating cells cannot span the distance between sensitized cells; therefore, anti-IgG links the Fc portions of the bound IgG molecules so that a lattice is formed, and agglutination is detected
A patient is suspected of having paroxysmal cold hemoglobinuria (PCH). Which pattern of reactivity is characteristic of the Donath-Landsteiner antibody, which causes this condition?
The antibody attaches to red blood cells at 4 C and causes hemolysis at 37 C
The antibody attaches to red cells at 37 C and causes agglutination at the IAT phase of testing
The antibody attaches to red cells at 22 C and causes hemolysis at 37C
The antibody attaches to red cells and causes agglutination at the IAT phase of testing
The antibody attaches to red blood cells at 4 C and causes hemolysis at 37 C
A positive reaction is seen at 37 degrees between the patient’s serum and ficin treated cells (including the autologous cells that are ficin treated) and negative results are obtained after adding antihuman globulin. Check cells were positive. What does this mean?
The patient has an alloantibody to a high frequency antigen since all the cells yielded reactions after 37 degrees
The patient has an autoantibody since the auto control was positive after 37 degrees
The patient has a ficin panagglutinin since all cells that were ficin treated reacted at 37 degrees
The patient has an alloantibody to a low frequency since all the cells were negative after adding antihuman globulin
The patient has a ficin panagglutinin since all cells that were ficin treated reacted at 37 degrees
In a serial dilution, you obtained positive results in your lower dilutions, positive in the middle ranges, and negative in the higher dilutions. What should you do?
Repeat the test
Report test as inconclusive
Report the titer of the highest dilution with a positive test
Report the titer of lowest dilution with a positive
Report the titer of the highest dilution with a positive test
If a patient has an antibody to anti-Kp(b), what is the challenge in finding compatible blood?
There is no challenge, Kp(b-) blood is readily available
Anti-Kp(b) is a “crossmatch compatible” antibody; therefore, the patient’s serum would be crossmatched against cells until a compatible unit is found
The Kp(b) antigen is a high frequency antigen; therefore, it would be difficult to find compatible red blood cells. Possibly siblings would be compatible
Anti-Kp(b) is a clinically insignificant antibody; so there would be no need to find red blood cells that are Kp(b-)
The Kp(b) antigen is a high frequency antigen; therefore, it would be difficult to find compatible red blood cells. Possibly siblings would be compatible
A patient has no history of a clinically significant antibody and the antibody screen using LISS enhancement at 37 C on to the antihuman globulin phase was negative. Check cells were positive. Which of the following crossmatch procedures is recommended?
Immediate spin, room temp major crossmatch
37 C LISS to antihuman globulin major crossmatch
Ficin related donor cells at 37 C to antihuman globulin
No crossmatch necessary
Immediate spin, room temp major crossmatch
In antibody detection procedures, a positive auto control after the addition of AHG is usually indicative of:
Inadequate washing
Positive DAT
Positive IAT
Rouleaux
Positive DAT
Why is rouleaux not found in the AHG phase of antibody screens?
High protein molecules are not reactive at 37 C
Patient cells are washed away before adding AHG
Patient serum is washed away before adding AHG
None of the above
Patient serum is washed away before adding AHG
An antibody screen and crossmatch for six units of red blood cells was performed. All units were 4+ incompatible at immediate spin, 3+ incompatible after adding antihuman globulin. The antibody screen was negative and there was no ABO discrepancy between the patient’s cells and serum. What is the most probable explanation for this?
The units of blood have been incorrectly ABO typed
The patient has an antibody to a high frequency antigen
The patient has an antibody to a low frequency antigen
The patients serum is not ABO compatible with the donor cells
The units of blood have been incorrectly ABO typed
What is the possible explanation for a nonreactive eluate?
Hemolytic disease of the newborn (HDN)
Positive DAT due to drugs
A warm autoantibody
All of the above
Positive DAT due to drugs
After the serum and cells were incubated for the appropriate time at 37 degrees, a tech washed the tubes by filling each tube one-third full of saline, centrifuging, decanting and repeating the procedure two additional times. AHG was added after a dry cell button was prepared. All results were negative; therefore check cells were added. All results were negative after the addition of the check cells. Choose the correct answer from below.
The results are most probably correct, and a “negative” result can be reported
The check cells are negative because the cells in the tubes were not properly washed.
Repeat the test exactly as done above but use a new bottle of check cells.
Add one more drop of check cells and re centrifuged
The check cells are negative because the cells in the tubes were not properly washed.
One drop of Coombs control cells was added to a negative antibody screen. No agglutination was observed after centrifugation. What course of action should be taken?
Report negative result
Report inconclusive result
Repeat the test
Add one more drop of check cells and re centrifuged
Repeat the test
A woman of childbearing age who was group AB negative was in need of whole blood. Since none was available, which of the following could be used?
Group AB positive whole blood
Group O negative packed cells
Group A negative whole blood
Group A positive packed cells
Group O negative packed cells
Why might some blood banking facilities prefer the use of monospecific IgG over Poly specific antihuman globulin (AHG) in their antibody screens?
Interference from naturally occurring warm antibodies in patient sera is reduced
Interference from naturally occurring cold antibodies in patient sera is reduced
There is more IgG in monospecific antisera than Poly specific reagents
Monospecific, IgG has been standardized
Interference from naturally occurring cold antibodies in patient sera is reduced
A tech treated all sixteen cells on a panel with DTT. What blood group system was destroyed?
Kidd system
Kell system
Lewis system
MNS system
Kell system
A patient has the Lewis phenotype Le(a-b-). An antibody panel reveals the presence of anti-Le(a). Another patient with the phenotype Le(a-b+) has a positive antibody screen; however, a panel reveals no conclusive antibody. Should anti-Le(a) be considered as possibility for the patient with the Le)a-b+) phenotype?
Anti-Le(a) should be considered as a possible antibody for this patient
Anti-Le(a) may be a possible antibody, but further studies are needed
Anti-Le(a) is not a likely antibody because even Le(b+) individuals secrete some Le(a)
Anti-Le(a) may not be found in the saliva, but the antibody is not detectable in the serum
Anti-Le(a) is not a likely antibody because even Le(b+) individuals secrete some Le(a)
A test to detect in vivo sensitized red blood cells is
An IAT
The addition of check cells
A DAT
An immediate spin crossmatch
A DAT
A group O, Rh negative man, aged 79 years with a negative antibody screen, was critically injured in a motor vehicle accident. The doctor wanted fresh whole blood, but whole blood was not available. Also, there was no group O, Rh negative blood in blood bank. What is the next best choice?
Group O Rh positive leukoreduced red blood cells and Group AB, Rh positive FFP
Group A, Rh negative leukoreduced red blood cells and group AB, Rh negative FFP
Group B, Rh negative leukoreduced RBCs and Group O, Rh negative FFP
Group AB, Rh negative leukoreduced RBCs and Group O, Rh negative FFP
Group O Rh positive leukoreduced red blood cells and Group AB, Rh positive FFP
Anti-S was identified in absorbed serum of a patient with warm autoimmune hemolytic anemia. If a RBC phenotype was performed on neat cells using an indirect antiglobulin test to ensure that the patient is negative for the S antigen, what would the technologists find?
The cells would have to be treated with ficin and then tested for the S antigen
Neat cells and commercial anti-S would yield a positive result due to IgM coating the neat cells
The patients neat cells would type negative for the S antigen
Neat cells and commercial anti-S would yield a positive result due to IgG coating the neat cells
Neat cells and commercial anti-S would yield a positive result due to IgG coating the neat cells
What characteristics are true of all three of the following antibodies? Anti-Fy(b), anti-S, and anti-M
All are detected with enzyme-treated cells
Require IAT technique for detection; usually not responsible for causing HDFN
May show dosage effect, all enhanced by acid
All may be detected at the AHG phase; all may cause HDN and transfusion reactions
May show dosage effect, all enhanced by acid
A sample appears to have anti-K; however, many other antigens must be ruled out. The tech can’t find enough k negative cells that are homozygous positive for the antigens not yet ruled out. What can be done to cells to remove the k antigen?
Treat the cells with AET
Treat the cells with papain
Treat the cells with ficin
Treat the cells with liquid nitrogen
Treat the cells with AET
How can cold autoantibody interference with ABO grouping be avoided?
Washing cells with normal saline cooled to 4C
Washing cells with normal saline warmed to 37C
Treating red cells with ficin prior to testing
Washing cells with normal saline at room temperature
Washing cells with normal salinewarmed to 37
Which cells are employed to remove autoantibody from the serum of a patient who had been transfused last month?
Coombs control red blood cells
Allogeneic cells with known antigens
Patient red blood cells
Panel red blood cells
Patient red blood cells
Light is generated when nucleotides are added to a growing strand of DNA in the process of:
Pyrosequencing
Ligase chain reaction
Strand displacement amplification
Branched DNA amplification
Pyrosequencing
An immunoassay is performed in the following manner to look for an antigen (Ag) in the patient serum: Patient serum + labeled Ag + known antibody (Ab) are added together and incubated. Unbound material is washed off. The amount of labeled Ag is then measured. What assay is performed?
Homogenous
Competitive
Capture
ELISA
Competitive
Extremely high analyte concentrations can cause false-negative results (hook effect) in which type of assay?
Homogenous competitive
Heterogenous competitive
Homogenous noncompetitive
Heterogenous noncompetitive
Homogenous noncompetitive
Use of microarrays consisting of either DNA or RNA to identify an unknown nucleic acid best describes:
In situ hybridization
DNA Chip Technology
DNA Chip Technology
… compound would be an appropriate label in a chemiluminescent assay?
Horseradish peroxidase
Ruthenium derivative
Ruthenium derivative
The production of insoluble complexes that absorb or scatter light but are too small to see directly is called:
Precipitation
Agglutination
Equivalence
Sensitization
Precipitation
To prepare 70 mL of 10% solution of acetic acid, how much acetic acid is needed?
0.7mL
7mL
10ml
1.4mL
7mL
In which of the following testing situations is there a direct relationship between the amount of bound label and the amount of patient antigen present?
Competitive radioimmunoassay using labeled antigen
Competitive enzyme immunoassay using labeled antigen
Noncompetitive enzyme immunoassay using a second labeled antibody
Any of the above
Noncompetitive enzyme immunoassay using a second labeled antibody
Which antibody has the highest avidity for an antigen?
IgG containing Fab that each have an affinity of xx10^-8/M
Secretory IgA containing Fab that each have an affinity of 4x10^-8/M
IgM containing Fab that each have affinity of 1x10^-8/M
IgE containing Fab that each have an affinity of 1x10^-9/<
IgM containing Fab that each have affinity of 1x10^-8/M
Serology is the study of:
WBCs
RBCs
Platelets
The liquid components of the blood. Especially antibodies
The liquid components of the blood. Especially antibodies
A 5 year old boy suffering from measels complained of back pain, chills, and stomach pain. his doctor revealed hemoglobinuria, bilirubinemia and hemoglobinemia. The child’s hemoglobin was 6. A donath landsteiner test was performed and showed the following:
Ctr sample: neg hemolysis
test sample: hemolysis
The results are consistent with what disorder
a. warm auto
b. cold auto
c. paroxysmal nocturnal hemoglobinuria
d. paroxysmal cold hemoglobinuria
d. paroxysmal cold hemoglobinuria
What is the purpose of coombs control cells aka check cells
Ensure AHG was not inactivated
To ensure that washing removed all unbound ab
To ensure AHG was no emitted
All of them
All of them
In a patient who has been recently transfused, a pos DAT may be due to:
Allo coating patient cell
Allo coating transfused cells
Ab to drug coated donor cells
None
Allo coating transfused cells
What can be concluded in a patient who has anti-K identified in his serum but phenotypes pos for the K antigen
a. Kell antisera omitted
b. Patient transfused with K pos blood
c. anti-K mis- ID
d. B and C
B and C
What is the pH of an acid eluate
3
Women need blood and she is B neg but the bank ran out of B neg blood with anti-C, D and E (oh nooo) what blood can you use instead so that she doesnt DIE BOOO
O rr
B R2R2
A rr
AB R1R1
O rr
