exam 1

Question 1

which immunoglobulin is larger: IgG or IgM?

Answer 1

IgM

Question 2

which immunoglobulin crosses the placenta?

Answer 2

IgG

Question 3

which immunoglobulin is most efficient at complement activation?

Answer 3

IgM

Question 4

which phase is IgG detected?

Answer 4

AHG (37 degrees C IAT)

Question 5

which phase is IgM detected?

Answer 5

immediate spin (room temp)

Question 6

Antibodies derived from multiple B-cell clones—recognize different epitopes on the same antigen.

Answer 6

polyclonal

Question 7

Antibodies derived from a single B-cell clone—recognize one specific epitope.

Answer 7

monoclonal

Question 8

these reagents detect recipient’s ABO antibodies (reverse typing).

Answer 8

A1 and B cells

Question 9

these reagents detect unexpected red cell antibodies in the patient.

Answer 9

screening cells

Question 10

reagents that determine ABO antigens on patient’s red cells (forward typing).

Answer 10

ABO antisera

Question 11

reagents used to identify specific antibodies using a panel of reagent red cells with known antigens.

Answer 11

panel cells

Question 12

reagent used to enhance antibody uptake by reducing zeta potential; increases rate of antibody uptake

Answer 12

LISS (Low Ionic Strength Solution)

Question 13

reagent that concentrates antibodies to enhance detection; concentrates the antibody in the test environment in LISS

Answer 13

PEG (Polyethylene Glycol)

Question 14

Modify red cell membranes, enhancing or destroying some antigens to aid antibody ID; removes negative charges from the red cell membrane which reduces the zeta potential; denatures some red cell antigens

Answer 14

Enzymes (e.g., ficin, papain)

Question 15

Detects antibodies already attached to patient’s red cells in vivo.

Answer 15

DAT

Question 16

Detects free antibodies in the plasma using test cells in vitro.

Answer 16

IAT

Question 17

Uses monospecific reagents (anti-IgG, anti-C3d) to determine which immunoglobulin or complement is coating red cells.

Answer 17

differential DAT

Question 18

what are the 2 most common conditions for a positive DAT

Answer 18

HDN(hemolytic disease of newborn) or
HTR(hemolytic transfusion reaction)
(Also: Autoimmune hemolytic anemia)

Question 19

most common false negatives in anti globulin testing?

Answer 19

Inadequate washing (neutralizes AHG)
Delay in testing
Loss of reactivity during incubation
Improper reagent storage

Question 20

List the most common false-positive reactions in antiglobulin testing

Answer 20

Overcentrifugation
Dirty glassware
Complement activation (e.g., from clotting)
Improper sample handling

Question 21

What is included in poly-specific antihuman globulin (AHG)

Answer 21

Anti-IgG
Anti-C3d/C3b

Question 22

Why are IgG-sensitized red cells used

Answer 22

To validate negative antiglobulin tests—confirms that AHG was added and is functional.

Question 23

Actual genetic makeup (e.g., AO)

Answer 23

Genotype

Question 24

Observed trait (e.g., blood type A)

Answer 24

Phenotype

Question 25

grading a tube method a 4+ looks like what?

Answer 25

solid button

Question 26

grading a tube method a 3+ looks like what?

Answer 26

large clumps, clear background

Question 27

grading a tube method a 2+ looks like what?

Answer 27

medium clumps

Question 28

grading a tube method a 1+ looks like what?

Answer 28

small clumps, turbid

Question 29

grading a tube method a 0 looks like what?

Answer 29

no agglutination

Question 30

grading a gel method a 4+ looks like what?

Answer 30

cells at the top

Question 31

grading a gel method a 3+ looks like what?

Answer 31

cells in upper 1/2

Question 32

grading a gel method a 2+ looks like what?

Answer 32

cells throughout

Question 33

grading a gel method a 1+ looks like what?

Answer 33

cells at bottom with some above

Question 34

grading a gel method a 0 looks like what?

Answer 34

cells at the bottom

Question 35

Both alleles of a gene must be identical to express the trait; Only expressed when both alleles are the same (OO)

Answer 35

recessive

Question 36

Equal expression of two different alleles; Both alleles expressed (AB)

Answer 36

codominant

Question 37

Only one allele of a gene is necessary to express the trait; One allele shows over another (A or B over O)

Answer 37

dominant

Question 38

Gene with no detectable product (e.g., O allele has no A/B antigen) Genes that do not express a detectable product

Answer 38

amorph

Question 39

exclusion of paternity when a child has a trait that neither parent shows; Alleged father lacks a gene that the child must have inherited.

Answer 39

direct exclusion

Question 40

Child’s marker does not match with what would be expected from mother + alleged father’s genotype; failure to find an expected marker in a child when the alleged father is apparently homozygous for the gene

Answer 40

Indirect Exclusion

Question 41

A person who inherits identical alleles; Two identical alleles (AA, BB)

Answer 41

homozygous

Question 42

A person who inherits different alleles; Two different alleles (AO, AB)

Answer 42

heterozygous

Question 43

two genes located on the same chromosome

Answer 43

cis

Question 44

Two genes located on opposite chromosomes.

Answer 44

trans