exam 2- serologic techniques Flashcards
____ the immunoglobulin that is usually responsible for direct agglutination
IgM
(T/F) Immunohematology relies mainly on hemagglutination
between antigens and antibodies
true
______ a result of antibody combining with antigen reaction
Direct agglutination
_____ test used to detect antibodies bound to RBCs in vivo and in vitro aka Coombs test
Antiglobulin test
____ scientists who showed that red cells can combine with antibody without being sensitized
Coombs, Mourant and Race (1945)
*____ is formed when an AHG reagent is added to IgG coated RBCs
lattice
(T/F) anti-IgG reacts with human globulin on RBCs or free in plasma/serum
true
____ an Antiglobulin test that detects antibody bound to RBCs in vivo
direct antiglobulin test (DAT)
the following are clinical basis of performing DAT except:
a. autoimmune hemolytic anemia
b. drug-induced hemolytic anemia
c. hemolytic disease of the newborn
d. hemolytic transfusion reaction
none of the above :)
all are valid reasons to perform DAT
(T/F) DAT can specify whether the detected ag is in RBCs or plasma
false
____ an antiglobulin test that detects in vitro sensitization of RBCs
Indirect antiglobulin test
(T/F) IAT can detect both antibody bound to RBCs and free ab in plasma
true
the ff are applications of IAT except:
a. antibody identification
b. crossmatch
c. extended antigen typing
d. weak D test
all are IAT applications
(T/F) AHG reagent contains both anti-IgG and anti-IgM
false
IgG only
(T/F) DAT is a one step test while IAT is two-step
true
which of the ff AHG reagents contains both anti-IgG and anti-complement? a. polyclonal b. polyspecific c. monoclonal d. monospecific
B
which of the ff AHG reagents contains multiple cell lines with different specificities ? a. polyclonal b. polyspecific c. monoclonal d. monospecific
A
which of the ff AHG reagents contains either anti-IgG or anti-complement? a. polyclonal b. polyspecific c. monoclonal d. monospecific
D
which of the ff AHG reagents contains an antibody specificity?
a. polyclonal
b. polyspecific
c. monoclonal
d. monospecific
C
at which step of IAT does ab molecules are allowed to attach to RBC antigens?
a. Incubation of RBCs with serum/antiserum
b. washing step
c. addition of AHG reagent
d. centrifugation
A
at which step of IAT does is agglutination sped up?
a. Incubation of RBCs with serum/antiserum
b. washing step
c. addition of AHG reagent
d. centrifugation
D
forcing cells to get closer
(T/F) check cells or sensitized RBCs is a confirming step that checks if AHG is not neutralized by free globulins
true
_____ is the component of AHG reagent
anti-IgG
_____ are substances added to the IAT reaction to enhance/ increase sensitivity of the method
Potentiators
which of the ff is not a potentiator? a. Bovine serum albumin b. LISS c . PEG d. PEG
none of the above
____ a potentiator that enables RBCs coated with antibody to get closer together by disrupting repulsion forces between them
albumin
____ a potentiator that removes water concentration from the antibodies and increases ab uptake by RBCs?
Polyethylene glycol (PEG)
which of the ff potentiators is good at detecting Rh antibodies?
a. Bovine serum albumin
b. LISS
c. proteolytic enzymes
d. PEG
A
which of the ff potentiators contain macromolecules and enhances antibody uptake?
a. Bovine serum albumin
b. LISS
c. proteolytic enzymes
d. PEG
B
(T/F) PEG increases the detection of clinically important antibodies
true
_____ are enzymes used in blood banking (3)
Bromelin (pinya), ficin (figs) and papain (papaya)
(T/F) enzyme use is done routinely in the lab
false
coz some ag are destroyed
(T/F) Enzyme treated RBCs are useful in sorting out mixtures of antibodies
true
which of the ff is NOT true about the action of proteolytic enzymes?
a. Enzymes cut negatively charged sialic acid molecules from polysaccharide side chains reducing RBC surface charge
b. can be used alone for antibody investigation
c. anti-Jka, Jkb and Rh are enhanced
d. destroys antigens MNSs, FYa, FYb and Xg
B
which of the ff are NOT possible sources of error in AHG testing?
a. Delay in adding/ reading the AHG (anti-IgG)
b. inadequate/excessive washing
c. failure to add AHG reagent
d. inactive AHG reagent
all are sources of error :)
(T/F) DAT positive cells can be used in IAT
false
cant do this coz in DAT, ab is already bound to RBCs = will get false pos result
____ an automated test technique used in DAT and IAT where glass beads or gel are used to “trap” agglutinated RBCs
Column Agglutination
(T/F) in column agglutination technique, Antibody coated cells are pelleted to the bottom of the column/ microtube while non-coated cells react with the AHG in gel column
false
the other way around
ab coated cells = rxn w/ AHG
non coated = pelleted
____ an automated test technique used in DAT and IAT; uses test tubes or microplates to immobilize and detect ag-ab rxns
solid-phase testing
(T/F) in a direct solid phase testing, RBCs or RBC membrance are attached to the microplate wells while in indirect test, the antibodies are in the wells
false
the other way around
direct: ab in well, add RBC
indirect: RBC in well, plasma/serum is added
(T/F) a positive solid phase testing is an appearance of a button in the well
false
direct phase neg rxn
____ is used in solid phase reactions; this is attached to the microplate wells and can bind IgGs
protein A
_____ information system interface in the lab
LIS - lab information system
____ testing patient or donor plasma/serum for
atypical/unexpected antibodies
antibody screen
(T/F) in ab screening the patient’s RBCs are tested using donor plasma
false
patient serum tested on donor RBC with known phenotype
