Lab Manual Definitions

Question 1

Absorption

Answer 1

removal of an unwanted antibody.

Question 2

Adsorption

Answer 2

providing an antibody with its corresponding antigen under optimal conditions so that the antibody will attach to the antigen, thereby removing the antibody from the serum

Question 3

Affinity

Answer 3

the bond between a single antigenic determinant and an individual combining site. A measure of the binding strength of an antibody for its epitope; a binding constant.

Question 4

Agglutination

Answer 4

the clumping together of red blood cells or any particulate matter resulting from interaction of antibody with its corresponding antigen.

Question 5

Agglutinin

Answer 5

an antibody that agglutinates cells.

Question 6

Agglutinogen

Answer 6

a substance that stimulates the production of an agglutinin, thereby acting as an antigen.

Question 7

Allele

Answer 7

one of two or more different genes that may occupy a specific locus on a chromosome.

Question 8

Allo-

Answer 8

prefix indicating differences within a species (e.g., an alloantibody is produced in one individual against the red cell antigens of another individual).

Question 9

Amorph

Answer 9

a gene that does not appear to produce a detectable antigen; a silent gene.

Question 10

Anti- A1 lectin

Answer 10

a reagent anti-A1 serum produced from the seeds of the plant Dolichos biflorus ; reacts with A1 cells but not with A subgroups.

Question 11

Anti-B lectin

Answer 11

a reagent anti-B serum produced from the seeds of the plant Bandeiraea simplicifolia.

Question 12

Antibody Screen

Answer 12

testing the patient’s serum with group O reagent red cells in an effort to detect atypical antibodies.

Question 13

Anti-H lectin

Answer 13

a reagent anti-H produced from the seeds of the plant Ulex europaeus.

Question 14

Antihuman globulin test (AGT)

Answer 14

test to ascertain the presence or absence or red cell coating by immunoglobulin G or complement, or both; uses a xenoantibody (rabbit antihuman serum) to act as a bridge between sensitized cells, thus yielding agglutination as a positive result.

Question 15

Antihuman serum

Answer 15

an antibody prepared in rabbits or other suitable animals that is directed against human immunoglobulin or complement, or both; used to perform the antihuman globulin or Coomb’s test. The serum may be either polyspecific or monospecific.

Question 16

Antiserum

Answer 16

a reagent source of antibody, as in a commercial antiserum.

Question 17

Autologous control

Answer 17

testing the patient’s serum with his or her own cells in an effort to detect autoantibody activity.

Question 18

Avidity

Answer 18

the strength with which a multivalent antibody binds to a multivalent antigen.

Question 19

Biphasic

Answer 19

reactivity occurring in two phases.

Question 20

Chimera

Answer 20

an individual who possesses a mixed cell population.

Question 21

Cis position

Answer 21

the location of two or more genes on the same chromosome of a homologous pair.

Question 22

Codominant

Answer 22

a pair of genes in which neither is dominant over the other; that is, they are both expressed.

Question 23

Coomb’s serum

Answer 23

see antihuman serum.

Question 24

Dosage

Answer 24

a phenomenon whereby an antibody reacts more strongly with a red cell carrying a double dose (homozygous inheritance of the appropriate gene) than with a red cell carrying a single dose (heterozygous inheritance) of an antigen.

Question 25

Elution

Answer 25

a process whereby cells that are coated with antibody are treated in such a manner as to disrupt the bonds between the antigen and antibody. The freed antibody is collected in an inert diluent such as saline or 7% albumin. This antibody serum then can be tested to identify its specificity using routine methods. The mechanism to free the antibody may be physical (heating, shaking) or chemical (ether, acid), and the harvested antibody-containing fluid is called an eluate.

Question 26

Enzyme treatment

Answer 26

a procedure in which red blood cells are incubated with an enzyme solution that cleaves some of the membrane’s glycoproteins, then washed free of the enzyme, and used in serologic testing. Enzyme treatment cleaves some antigens and exposes others.

Question 27

Ficin

Answer 27

a proteolytic enzyme derived from the fig.

Question 28

Genotype

Answer 28

an individual’s actual genetic makeup.

Question 29

Hemolysin

Answer 29

an antibody that activates complement, leading to cell lysis.

Question 30

Homozygous

Answer 30

possessing a pair of identical alleles.

Question 31

In vitro

Answer 31

outside the living body, as in a laboratory setting.

Question 32

In vivo

Answer 32

inside the living body.

Question 33

Isogglutinins

Answer 33

Also called isoantibodies,the ABO antibodies anti-A, anti-B, and anti-A,B, which are expected to be found in serum.

Question 34

Lectin

Answer 34

proteins present in plants (usually seeds), which bind specifically to carbohydrate determinants and agglutinate erythrocytes through their cell surface of oligosaccharide determinants.

Question 35

Low ionic strength solution (LISS)

Answer 35

a type of potentiating medium in use for serologic testing. Reducing the ionic strength of the red cell suspending medium increases the affinity of the antigen for its corresponding antibody such that sensitivity can be increased and incubation time decreased. LISS contains glycine or glucose in addition to saline.

Question 36

Major crossmatch

Answer 36

compatibility testing procedure using recipient’s serum and donor red cells.

Question 37

Minor crossmatch

Answer 37

compatibility testing procedure using recipient’s red cells and donor’s serum.

Question 38

Monoclonal

Answer 38

antibody derived from a single ancestral antibody-producing parent cell.

Question 39

Phenotype

Answer 39

the outward expression of genes ( e.g. a blood type). On blood cells, serologically demonstrable antigens constitute the phenotype, except those sugar sites that are determined by transferases.

Question 40

Prozone

Answer 40

incomplete lattice formation caused by an excess of antibody molecules relative to the number of antigen sites, resulting in false-negative reactions.

Question 41

Xeno-

Answer 41

prefix indicating differing species. For example, a xenoantibody is an antibody produced in one species against an antigen present in another species. Synonym is hetero-.

Question 42

Antenatal

Answer 42

Occurring before birth

Question 43

Antithetical

Answer 43

Referring to antigens that are the product of allelic gene (e.g. K and k)

Question 44

Heterozygous

Answer 44

possessing different alleles at a given locus