CHT CHS Certification – Serology Questions and Answers | 2026/2027 |
Complete Certification Exam Preparation Study Guide A+ Grade
It is possible to convert the plasma
into serum by recalcifying the plasma and allowing coagulation to occur. - (ANSWER)Calcium is added to
the plasma to form a complex with the citrate present in the anti-coagulant. This restores a normal
ionized calcium level allowing clotting to occur.
Polyspecific antiserum
can be______ with lymphocytes to determine if there is a single antibody or multiple
antibodies. - (ANSWER)absorbed
Another application of lymphocyte
absorption is to use the patient's own cells to remove_____. Absorption can be performed
at cold or warm temperatures depending on the type of antibody. - (ANSWER)autoantibody
_________ are typically
cold reacting (4oC) and________are typically warm reacting (22-37oC). - (ANSWER)Autoantibodies
B cell antibodies
Patient serum may contain autoantibodies and/or IgM antibodies that may interfere the binding of
anti-HLA IgG antibodies to the antigen. In complement dependent assays (CDC), IgM antibodies
can activate complement; potentially leading to ___________. - (ANSWER)false positive reactivity.
DTT - (ANSWER)dithiothreitol, also known as Cleland's Reagent
DTT inactivates IgM molecules by cleaving the _________ in the
pentamer structure. - (ANSWER)disulphide bonds
,CHT CHS Certification – Serology Questions and Answers | 2026/2027 |
Complete Certification Exam Preparation Study Guide A+ Grade
Heat inactivation works by cleaving the disulphide bonds in the
pentamer structure, but is less specific than _____. - (ANSWER)DTT.
ALA - (ANSWER)therapeutic antilymphocyte
antibodies
Thymoglobulin - (ANSWER)purified, pasteurized, gamma immune globulin,
obtained by immunization of rabbits with human thymocytes
OKT3 - (ANSWER)a murine IgG monoclonal antibody directed against CD3
If these therapeutic antilymphocyte
antibodies are present in the patient serum, they can cause_______ reactivity in
T cell cytotoxic assays. - (ANSWER)false positive
ALA removal is accomplished by absorption using _____coated with anti-rabbit or anti-mouse
immunoglobulin for Thymoblobulin or OKT3, respectively. - (ANSWER)magnetic beads
serum preparations - (ANSWER)1. Recalcificiation of plasma
2. Adsorption with lymphocytes
3. Inactivation of IgM antibodies
a. DTT treatment
b. Heat Inactivation
4. Depletion of therapeutic anti-lymphocyte antibodies from serum
Why is calcium added to plasma to convert it to serum? - (ANSWER)Calcium is added to the plasma to
combine with the citrate present in the anticoagulant.
, CHT CHS Certification – Serology Questions and Answers | 2026/2027 |
Complete Certification Exam Preparation Study Guide A+ Grade
This restores a normal ionized calcium level and allows clotting to occur.
At what temperature should serum absorption with lymphocytes be performed? - (ANSWER)Typically,
auto-antibodies are cold reacting and should be absorbed at 4oC while alloantibodies
are warm reacting and should be absorbed at 37oC.
DTT treatment is more specific than heat treatment in
removing IgM antibodies. However, DTT can also affect the _______ in IgG antibodies. -
(ANSWER)disulfide bonds
What happens if we don't remove OKT3 prior to cytotoxicity assays? - (ANSWER)OKT3 is a monoclonal
antibody directed against the CD3 molecule. Therefore, the
binding of OKT3 to any CD3+ cell will activate complement and lyse the target cell. This results
in falsely positive reactivity.
Lymphocytes have a density of_______ - (ANSWER)~1.077 g/ml.
Cells with a higher density than FH - (ANSWER)red cells and granulocytes
cells of a lower density than lymphocytes - (ANSWER)platelets
isolation of cells from lymph nodes or spleen is normally fast and simple and leads to greater _____ and
______ - (ANSWER)cell yield
viability.
Obtaining lymphocytes from spleen will require
an additional FH step along with purification steps due to a large number of contaminating cells,
Complete Certification Exam Preparation Study Guide A+ Grade
It is possible to convert the plasma
into serum by recalcifying the plasma and allowing coagulation to occur. - (ANSWER)Calcium is added to
the plasma to form a complex with the citrate present in the anti-coagulant. This restores a normal
ionized calcium level allowing clotting to occur.
Polyspecific antiserum
can be______ with lymphocytes to determine if there is a single antibody or multiple
antibodies. - (ANSWER)absorbed
Another application of lymphocyte
absorption is to use the patient's own cells to remove_____. Absorption can be performed
at cold or warm temperatures depending on the type of antibody. - (ANSWER)autoantibody
_________ are typically
cold reacting (4oC) and________are typically warm reacting (22-37oC). - (ANSWER)Autoantibodies
B cell antibodies
Patient serum may contain autoantibodies and/or IgM antibodies that may interfere the binding of
anti-HLA IgG antibodies to the antigen. In complement dependent assays (CDC), IgM antibodies
can activate complement; potentially leading to ___________. - (ANSWER)false positive reactivity.
DTT - (ANSWER)dithiothreitol, also known as Cleland's Reagent
DTT inactivates IgM molecules by cleaving the _________ in the
pentamer structure. - (ANSWER)disulphide bonds
,CHT CHS Certification – Serology Questions and Answers | 2026/2027 |
Complete Certification Exam Preparation Study Guide A+ Grade
Heat inactivation works by cleaving the disulphide bonds in the
pentamer structure, but is less specific than _____. - (ANSWER)DTT.
ALA - (ANSWER)therapeutic antilymphocyte
antibodies
Thymoglobulin - (ANSWER)purified, pasteurized, gamma immune globulin,
obtained by immunization of rabbits with human thymocytes
OKT3 - (ANSWER)a murine IgG monoclonal antibody directed against CD3
If these therapeutic antilymphocyte
antibodies are present in the patient serum, they can cause_______ reactivity in
T cell cytotoxic assays. - (ANSWER)false positive
ALA removal is accomplished by absorption using _____coated with anti-rabbit or anti-mouse
immunoglobulin for Thymoblobulin or OKT3, respectively. - (ANSWER)magnetic beads
serum preparations - (ANSWER)1. Recalcificiation of plasma
2. Adsorption with lymphocytes
3. Inactivation of IgM antibodies
a. DTT treatment
b. Heat Inactivation
4. Depletion of therapeutic anti-lymphocyte antibodies from serum
Why is calcium added to plasma to convert it to serum? - (ANSWER)Calcium is added to the plasma to
combine with the citrate present in the anticoagulant.
, CHT CHS Certification – Serology Questions and Answers | 2026/2027 |
Complete Certification Exam Preparation Study Guide A+ Grade
This restores a normal ionized calcium level and allows clotting to occur.
At what temperature should serum absorption with lymphocytes be performed? - (ANSWER)Typically,
auto-antibodies are cold reacting and should be absorbed at 4oC while alloantibodies
are warm reacting and should be absorbed at 37oC.
DTT treatment is more specific than heat treatment in
removing IgM antibodies. However, DTT can also affect the _______ in IgG antibodies. -
(ANSWER)disulfide bonds
What happens if we don't remove OKT3 prior to cytotoxicity assays? - (ANSWER)OKT3 is a monoclonal
antibody directed against the CD3 molecule. Therefore, the
binding of OKT3 to any CD3+ cell will activate complement and lyse the target cell. This results
in falsely positive reactivity.
Lymphocytes have a density of_______ - (ANSWER)~1.077 g/ml.
Cells with a higher density than FH - (ANSWER)red cells and granulocytes
cells of a lower density than lymphocytes - (ANSWER)platelets
isolation of cells from lymph nodes or spleen is normally fast and simple and leads to greater _____ and
______ - (ANSWER)cell yield
viability.
Obtaining lymphocytes from spleen will require
an additional FH step along with purification steps due to a large number of contaminating cells,
