Trans lecture 1 Flashcards
(223 cards)
1
Q
How can the genotype be determined from the phenotype?
A
The genotype can only be inferred or derived by deduction from the phenotype.
2
Q
What techniques can be used to determine the genotype?
A
The genotype can be determined by molecular techniques or family studies.
3
Q
What is specificity in immunology?
A
Specificity refers to the recognition of the antigen and its corresponding antibody molecule.
4
Q
Give an example of specificity in immunology.
A
A commercial anti-sera anti-B will react with red cells that possess the B antigen and will not react with cells that lack the B antigen.
5
Q
What does potency describe in immunology?
A
Potency describes the strength of the agglutination reaction.
6
Q
Which blood group system is the most important?
A
The ABO system is the most important of all blood groups.
7
Q
Why is ABO typing important for blood donors and patients who may require transfusion?
A
ABO typing is important to determine compatibility and prevent red cell lysis or death from incompatible transfusions.
8
Q
What is the ABO reciprocal relationship?
A
The forward + reverse must be opposite for it to be valid.
9
Q
Why is the ABO reciprocal relationship important?
A
The inverse reciprocal relationship between forward and reverse testing is a ‘check’ or ‘validation’ of the patient’s blood type.
10
Q
What should be done if a discrepancy exists in ABO typing?
A
A discrepancy in ABO typing must be resolved before any transfusion can occur.
11
Q
What populations may have variation in ABO group frequencies?
A
Selected populations and different ethnic populations may have variation in ABO group frequencies.
12
Q
Which population is Group B blood type seen more frequently in?
A
Group B blood type is seen more frequently in the Black and Asian populations than in Caucasian populations.
13
Q
What are some examples of red cell antigen differences seen by ethnicity?
A
Examples include U and Duffy antigens, which are more common in African Americans and protect from malaria.
14
Q
What are the immunoglobulins of the ABO system and how do they develop?
A
The immunoglobulins of the ABO system are IgM and ‘naturally’ occurring. They develop due to exposure to bacteria or substances with a similar chemical make-up as the A and B antigens.
15
Q
What can ABO antibodies activate and when do they react strongly?
A
ABO antibodies can activate complement and they react strongly at room temperature or even colder.
16
Q
What are isoagglutinins and when are they detected in newborns?
A
Isoagglutinins are antibodies anti-A, anti-B, and anti-AB. They start to develop in newborns at birth but are not detected until 3 to 6 months of age.
17
Q
Why are reverse testing not done on newborns?
A
Reverse testing is not done on newborns as maternal antibodies will be detected on cord cells, making the results invalid.
18
Q
How is ABO typing determined in newborns?
A
ABO typing in newborns is determined solely on the forward reactions, as reverse testing is not performed.
19
Q
What happens to ABO antibody production as we age?
A
ABO antibody production declines as we age, sometimes to the point where it is too low to detect, resulting in a discrepancy in ABO typing.
20
Q
When does ABO antibody production typically peak?
A
ABO antibody production typically peaks around the age of 5 to 10.
21
Q
How are most blood group antigens inherited?
A
Most blood group antigens are inherited co-dominantly.
22
Q
What are some examples of blood group inheritance patterns?
A
Most blood group antigens are inherited co-dominantly.
23
Q
What is the reaction pattern observed when red cells are transfused to a Bombay patient?
A
Immediate red cell lysis
24
Q
What antigens do Bombay individuals lack on their red cells?
A
A, B, and H antigens
25
What antibodies do Bombay individuals possess in their sera?
Anti-A, anti-B, and anti-H
26
When is anti-H detected in routine ABO grouping?
It is detected in pre-transfusion testing
27
Which red cells would agglutinate when Bombay sera is tested with group O screening cells and group O donor cells?
Group O screening cells and group O donor cells
28
What is the significance of the Bombay phenotype in blood transfusion?
All normal ABO groups are incompatible when cross-matched for Bombay individuals
29
What is the recommended source of blood for transfusion to a Bombay patient?
Blood from another Bombay individual
30
Where can donors for Bombay individuals be sought?
Among blood relatives (especially siblings) or from the CBS rare donor file
31
What confirmatory testing can be done to identify Bombay phenotype?
Agglutination of A, B, AB, and O cells and negative anti-H lectin
32
Which lectin is most important for determining A1 antigen specificity?
Dolichos biflorus
33
What does the agglutination of Dolichos biflorus lectin indicate?
A1 antigen (if no agglutination, indicates A2 antigen)
34
What is the H antigen specificity of Ulex europaeus lectin?
Secretor or Bombay phenotype
35
What is the N antigen specificity of Vicia graminea lectin?
Renal dialysis patients have N- and will have to transfuse N-
36
Which lectin belongs to MNS-sU-u and has M antigen specificity?
Iberis amara
37
What type of activation does Arachis hypognea lectin cause in polyagglutination syndromes?
T activation
38
Which lectin agglutinates B cells?
Bandeiraea simplicifolia
39
What are ABO subgroups and how do they differ from other ABO blood types?
Subgroups are phenotypes that differ in the amount of antigen on red cells and the secretions present in body fluids
40
How are ABO subgroups classified?
Based on different levels of expression of A or B antigens on red blood cells
41
What are the major subgroups of group A individuals?
A1 and A2
42
What is the approximate percentage of group A individuals who are A1?
Approximately 80%
43
What is the approximate percentage of group A individuals who are A2?
Approximately 20%
44
How does the amount of antigen expressed on red cell membrane differ between group A1 and A2 subgroups?
Group A1 individuals have approximately 2 million antigen sites per red cell, while group A2 individuals have approximately 500,000 sites
45
Which subgroup of group A individuals has more H antigen on their red cells?
Group A2 individuals
46
Can group A2 subgroup be determined serologically?
No, it can only be determined based on genetic testing
47
What is the qualitative difference between A1 and A2 subgroups?
A2 subgroup has more H antigen on their red cells than A1 subgroup
48
What percentage of individuals belong to ABO subgroups?
1% to 8%
49
What group does acquired B phenomenon fall into?
Group II discrepancies
50
What diseases is acquired B phenomenon commonly seen in?
Digestive tract diseases like cancer of the colon
51
Which patients with a lower GI tract disease state are commonly associated with acquired B phenomenon?
Group A patients
52
What are some examples of lower GI tract diseases associated with acquired B phenomenon?
Colon or rectal cancers, bowel obstruction, gram negative septicemia
53
What is the cause of acquired B phenomenon?
Removal (deacetylation) of the acetyl group of the group A immunodominant sugar into D-galactosamine
54
What sugar does the modified immunodominant sugar in acquired B phenomenon resemble?
D-galactose (group B immunodominant sugar)
55
What is the term for weak agglutination caused by the cross-reaction of D-galactosamine with anti-B antisera?
Pseudo-B
56
What happens to the A1 antigen in acquired B phenomenon?
It is produced at the expense of the pseudo B antigen
57
What happens to the ABO type once the patient has recovered from acquired B phenomenon?
It returns to normal
58
What type of reactions are observed in acquired B? (AUTO test)
Negative reactions - anti-B in serum does not agglutinate autologous RBC's with the acquired B antigen
59
Under what pH conditions will acquired anti-B not agglutinate?
pH > 8.5 or < pH 6.0
60
What reduces the reactivity of cells tested against anti-B in acquired B phenomenon?
Treating RBC's with acetic anhydride
61
How are normal B cells affected by acetic anhydride treatment?
They are not affected
62
What can occur with some anti-B antisera in acquired B phenomenon?
Cross-reaction
63
What should be transfused if transfusion is required in acquired B phenomenon?
Group A blood
64
What causes Category III discrepancies?
Protein or plasma abnormalities
65
What does the presence of abnormal protein in plasma result in category III discrepancies?
Rouleaux formation or pseudoagglutination
66
What may increased levels of globulin indicate in Category III discrepancies?
Patients with Multiple Myeloma, Waldenström's macroglobulinemia, other plasma cell dyscrasias, and possibly advanced cases of Hodgkin's lymphoma
67
What can cause category III discrepancies in individuals?
High levels of fibrinogen, treatment with plasma expanders like dextran, and presence of Wharton's jelly - cord cells
68
What is the resolution for category III discrepancies due to rouleaux formation?
Washing the patient cells several times with 0.9% saline and retest
69
What is the method of resolving category III discrepancies caused by excess Wharton's jelly in cord cells?
Wash cells 6-8 times with 0.9% saline
70
What causes category IV discrepancies?
Discrepancy between forward and reverse typing
71
What are some possible causes of category IV discrepancies?
Cold reacting autoantibodies, unexpected ABO isoagglutinins, unexpected non-ABO alloantibodies, and more than one ABO type circulating due to transfusion or BM/stem cell transplant
72
How can forward typing discrepancies in category IV be resolved?
By incubating cells at 37°C, washing at least 3 times with saline, and then repeat testing
73
What can disperse IgM agglutination in category IV discrepancies?
Treat cells with dithiothreitol (DTT)
74
What is the method of resolving forward typing discrepancies in serum/plasma testing?
Perform strict pre-warmed technique and then perform testing, potentially converting to the AHG phase of testing
75
Which ABO phenotype possesses the most H antigens?
Group O RBC's
76
Which ABO phenotype possesses the fewest H antigens?
Group A1B RBC's
77
In which ABO phenotype are H antibodies almost never detected?
Group B individuals
78
What are the characteristics of anti-H antibodies?
Relatively weak reacting, primarily react at room temperature, considered clinically insignificant
79
What can cause discrepant results in reverse testing?
H antibodies
80
What is the term used to refer to the secretion of blood type antigens A, B, and H soluble antigens into body fluids?
Secretor
81
Which fluids can be used to detect A, B, and H soluble antigens in secretors?
Saliva, sweat, tears, semen, breast milk, amniotic fluid, urine, bile
82
What are the two alleles that control ABH secretion?
Se (dominant) and se (recessive)
83
What percentage of the population are secretors?
Approximately 80%
84
What is the inheritance pattern of secretor genes relative to ABO and H genes?
Inherited independently
85
What soluble antigens are secreted by group O individuals?
H soluble antigen
86
What soluble antigens are secreted by group A individuals?
A and H soluble antigens
87
What soluble antigens are secreted by group B individuals?
B and H soluble antigens
88
What soluble antigens are secreted by group AB individuals?
A, B, and H soluble antigens
89
What is the practical application of the interaction between ABO, H, and secretor genes?
Expression of soluble antigens in body fluids
90
What is the purpose of the inhibition neutralization test for the detection of ABH substances in saliva?
To determine secretor status
91
What happens during antibody neutralization in the inhibition neutralization test?
Soluble antigens in saliva neutralize the antibodies
92
What happens during agglutination inhibition in the inhibition neutralization test?
Soluble antigens prevent agglutination with known antigens
93
In the inhibition neutralization test, how is the reaction interpreted for secretors?
Negative for agglutination but positive for secretor status
94
In the inhibition neutralization test, how is the reaction interpreted for non-secretors?
Positive for agglutination but negative for secretor status
95
What is the first part of the inhibition/neutralization test procedure?
Mixing saliva with diluted commercial antisera
96
What is the second part of the inhibition/neutralization test procedure?
Testing for agglutination inhibition using commercial red cells
97
What fluids can be used to collect samples for the inhibition-neutralization test?
Saliva
98
What are the possible indications of a positive antibody screen?
Possible indications of a positive antibody screen include spontaneous agglutination, significant hemolysis, and a decrease in agglutination strength over time.
99
How many screening cells are typically used in an antibody screen?
Depending on the hospital, you might only have 2 screening cells.
100
What is the significance of a positive antibody screen?
A positive antibody screen indicates the presence of antibodies in the patient's plasma/serum due to exposure to red cell antigens through pregnancy or transfusion.
101
What is the purpose of performing an antibody identification?
Antibody identification is performed to determine the specific antibodies present in the patient's plasma/serum, which helps in selecting compatible blood for transfusion.
102
What is the difference between warm and cold antibodies?
Warm antibodies are IgG antibodies, while cold antibodies are IgM antibodies.
103
What is the purpose of testing patient red cells?
Patient red cells are used to identify patient red cell antigens, such as ABO and Rh typing, and phenotype testing.
104
How are patient red cells prepared for testing?
Patient red cells are prepared into a 3-5% cell suspension for tube testing or 0.8% for GEL methodology, and the suspension must be in an EDTA tube.
105
What is the purpose of testing blood donor cells?
Blood donor cells are used to identify blood donor red cell antigens, such as ABO and Rh typing, and phenotype testing.
106
What are the sources of antibodies used in routine testing?
Sources of antibodies include patient plasma/serum, commercial anti-sera, and commercially known antibodies.
107
How is ABO/Rh typing performed?
ABO/Rh typing is performed by combining commercial antisera (known antibodies) with patient red cells (unknown antigens).
108
What is the purpose of ABO serum typing?
ABO serum typing detects the presence or absence of ABO antibodies (anti-A, anti-B) in a patient's plasma using commercial red cells with known antigens.
109
What does an antibody screen test for?
An antibody screen test detects the presence of pre-formed antibodies in a patient's plasma/serum due to exposure to red cell antigens through pregnancy or transfusion.
110
How are immune red cell antibodies developed?
Immune red cell antibodies develop in individuals who lack a specific red cell antigen and are exposed to the foreign antigen through pregnancy or transfusion.
111
What is the purpose of using Rogan for O- moms during pregnancy?
Rogan is given to O- moms to prevent the development of antibodies against the baby's red cells, which can lead to hemolytic disease of the newborn.
112
What are the two antigens responsible for ABO types?
A and B
113
What are the two antibodies responsible for ABO types?
Anti-A and Anti-B
114
How many genes are associated with the ABO system?
Three
115
What type of inheritance is associated with gene A in the ABO system?
Co-dominant
116
What type of inheritance is associated with gene B in the ABO system?
Co-dominant
117
What type of inheritance is associated with gene O in the ABO system?
Silent gene or amorph – NO detectable antigens
118
When both A and B genes are inherited, how are the antigens expressed on red blood cells?
Equally
119
Are recessive or dominant inheritance patterns common in blood group system genetics?
No
120
On which chromosome are the A and B genes found?
Chromosome 9
121
How many alleles are co-dominant in the ABO system?
Two
122
Will an A or B gene always be expressed when inherited?
Yes
123
What will be expressed if an individual inherits the O gene?
No A or B antigens
124
What type of gene is the O gene?
Amorph (silent gene)
125
When does the O gene get expressed?
When inherited from both parents (OO)
126
What gene can an A/A parent pass along?
An A gene
127
What genes can an A/O parent pass along?
An A or O gene
128
What gene can a B/B parent pass along?
A B gene
129
What genes can a B/O parent pass along?
A B or O gene
130
What gene can an O/O parent pass along?
An O gene
131
What genes can an AB parent pass along?
An A or B gene
132
What is the H antigen controlled by?
The H gene
133
Is the H gene dominant or recessive?
Dominant
134
What is critical for the ability to express A and B antigens?
Formation of H antigen
135
Which antigens are found on a common carbohydrate structure?
ABO antigens
136
What do the gene products of ABO alleles need as the acceptor molecule?
H antigen
137
What is the common structure for the A, B, and H antigens?
Oligosaccharide chain
138
What do the A and B genes code for?
Enzymes that add sugars to the H antigen
139
What is the immunodominant sugar for group A specificity?
N-acetylgalactosamine
140
What is the immunodominant sugar for group B specificity?
D-galactose
141
What is the type O rich in?
Unconverted H antigen
142
Why are Group O individuals rich in H antigens?
Because they have no A or B genes to convert the H antigen to A or B antigens
143
What is the result of autoantibodies in patient cells?
Spontaneous agglutination resulting in a positive DAT.
144
If a cold autoantibody reacts with all adult cells, what will the reverse cells show?
Agglutination.
145
What can you do if you are expecting agglutination in reverse but it is still negative?
Perform autoabsorption - patient serum + patient cells.
146
What are unexpected isoagglutinins?
Naturally occurring anti-A1 or A1 and A1B in individuals who are A2 or A2B.
147
How can you determine the specificity of an antibody?
Test at least 3 samples of A1, A2, B, O cells and auto control, and look at the reaction pattern.
148
What may the presence of anti-A1 antibody indicate?
If antibody agglutinates only A1 cells, it can be identified as anti-A1 present.
149
If anti-A1 is detected, what additional test should be performed?
The patient must be tested with Dolichos biflorus.
150
What cold-reacting antibodies may be detected in reverse testing?
Anti-M, anti-N, anti-Lea, and anti-Leb.
151
Why might reverse cells possess certain antigens?
Reverse cells are pooled, so they may possess antigens if the patient has a specific antibody.
152
If a patient has a specific antibody, how can you test for it?
Perform a panel ID on the patient serum and test A1 and/or B cells negative for the specific antibody.
153
What can cause agglutination in forward typing?
Ag/AB complexes (acriflavine/anti-acriflavine) adsorbing onto patient RBC's.
154
How can you resolve agglutination in forward typing caused by ag/AB complexes?
Wash in saline several times and repeat testing.
155
What is the cis-AB phenotype?
Inheriting both A and B genes from one parent on the same chromosome, while the other parent is group O.
156
What is the discrepancy in serum of most cis-AB people?
Weak anti-B.
157
Where can you find a chart for discrepancies between forward and reverse grouping?
Page 143 -144 of 'Modern Blood Banking and Transfusion Practices, 7th Edition'.
158
What should you look for in the chart for discrepancies between forward and reverse grouping?
Reaction pattern, cause, and resolution.
159
What is Landsteiner's Rule or Law based on?
Mendel's theories/laws.
160
According to Landsteiner's Rule, what happens if you possess a red cell antigen?
You will not have the corresponding antibody, except for alloantibodies.
161
What does Landsteiner's Rule state about the coexistence of antigens and antibodies?
Corresponding antigens and antibodies will not coexist in individuals.
162
In the ABO system, what antibodies are found in the plasma if the A antigen is absent on the patient's red cells?
Anti-A antibodies.
163
What antibodies are found in the plasma if the B antigen is absent on the patient's red cells?
Anti-B antibodies.
164
If both A and B antigens are absent from red cells, what antibodies will be found in the plasma?
Both anti-A and anti-B antibodies.
165
Which blood group is considered the Universal Donor for red cells?
Group O.
166
Which blood group can receive all blood types, A, B, AB, and O?
Group AB.
167
What are lipids and proteins that cause lysis of red blood cells?
Potent hemolysins.
168
Why must the ABO of a patient and blood donor be compatible during transfusion?
Mismatch can lead to death - 10 cc of ABO mismatched blood can kill.
169
Which blood group is considered the Universal Donor for plasma?
Group AB.
170
Where are antigens found and where are antibodies found?
Antigens are found on red cells, and antibodies are found in plasma or serum.
171
What must be known if the unknown variable is the antibody?
The known variable must be the antigen.
172
What are the sources of antigens in routine testing?
Red cells, reagent red cells, patient, blood donor.
173
What are reverse cells used for?
Reverse typing to determine the presence/absence of corresponding antibodies.
174
What are screening cells used for?
AB Screen, to test for the presence of A or B antigen or antibodies.
175
What are panel cells used for?
Antibody identification to determine the specificity of antibodies.
176
What are Coombs Control cells used for?
To verify if it is a true negative result in antigen testing.
177
What is the evidence of reagent red cell deterioration?
Not mentioned in the course notes.
178
What is the best resolution for Category I discrepancies in ABO blood typing?
Enhancing weak or missing reaction by incubating reverse tubes with A1 and B cells.
179
What is chimerism in the context of ABO blood typing discrepancies?
It refers to individuals with two distinct cell populations existing in one person.
180
What is the difference between true and artificial chimerism?
True chimerism occurs only in twins and is lifelong, while artificial chimerism is common but not lifelong.
181
What can cause artificial chimerism?
Artificial chimerism can occur due to transfusion, BM transplant, exchange transfusion, or fetal-maternal bleed.
182
What are the possible causes for weak or missing red cell antigens in Category II discrepancies?
Possible causes include subgroups of A or B, weakened antigens in leukemias, Hodgkin's disease, acquired 'B' phenomenon.
183
What are blood group-specific soluble substances (BGSS) and their effect on blood typing?
BGSS substances neutralize anti-A/anti-B antisera, resulting in a negative reaction in forward grouping.
184
How can discrepancies due to BGSS be resolved?
Patient RBC's can be washed with saline to remove the substance, correcting the forward and reverse discrepancy.
185
What can cause weak or missing reactions in RBC grouping besides BGSS?
Antibodies to low-incidence antigens or low incidence antibody in antisera can cause such discrepancies.
186
How can discrepancies due to weak or missing reactions be resolved?
Repeat testing using reagents from different lots or different manufacturers can help identify low-incidence antibodies.
187
How can weak reacting antigens in Category II discrepancies be enhanced?
Extending the incubation at room temperature to 30 minutes can enhance antigen/antibody association.
188
What is the Acquired B Phenomenon?
It refers to weakened expression of the B antigen in the forward typing, often caused by disease states like leukemia.
189
What percentage of A2B individuals produce anti-A1?
22% to 35%
190
What is the main feature of the A3 subgroup?
Mixed field reaction with anti-A and anti-A,B antisera
191
Which gene is dominant over the A2 gene?
A1 gene
192
What is the purpose of A1 lectin?
To differentiate between A1 and A2 subgroups
193
What percentage of A2 people naturally have A1 antibody?
Approximately 8%
194
Is it necessary to distinguish between A1 and A2 phenotypes for transfusion purposes?
No, unless the patient has a reacting A1 antibody
195
What is the main characteristic of the A3 subgroup?
Mixed field (MF) reaction with anti-A and anti-A,B antisera
196
Which subgroup is very rare, approximately 1/40,000?
Ax
197
How can weak A subgroups be differentiated serologically?
Perform forward typing for presence of A and H antigens, perform reverse typing of ABO isoagglutinins, perform adsorption and elution testing with anti-A, perform saliva testing (neutralization/inhibition) to detect A and H substances
198
What does a weak A phenotype indicate?
Several ways to differentiate weak A subgroups serologically
199
What is the significance of a 2+ reaction in weak A subgroups?
It is a significant but weak reaction
200
What type of reaction does anti-A1 antibody cause?
IgM, agglutinates at RT (room temperature) and binds complement well
201
What can clinically significant anti-A1 cause?
Red cell destruction of transfused cells or HDFN (hemolytic disease of the fetus and newborn)
202
What is the cause of ABO discrepancies?
Most discrepancies are caused by technical/clerical errors
203
Do transfusions with ABO discrepancies need to be resolved?
Yes, ABO discrepancies must be resolved
204
What is the purpose of adsorption-elution methods in ABO discrepancies?
To determine the presence of B substance in saliva
205
What should you give in emergency situations if there is no time to rematch?
O- unmatched blood
206
When may a discrepancy be seen in both the forward and reverse typing?
When there is a discrepancy in both the serum and cells
207
What is the first step in identifying the source of an ABO discrepancy?
Identifying the source of the problem
208
What should you always suspect with an ABO discrepancy?
The weakest reaction
209
What may indicate an ABO discrepancy?
Agglutination strength of typing anti-sera is weaker than expected
210
What technical errors can result in ABO discrepancies?
Blood sampling errors, tube labelling errors, failure to add sample, reagents not added or incorrect reagent added, contaminated reagents, presence of hemolysis, incorrect sample tested/sample mix-up, not following manufacturer's instructions, using uncalibrated centrifuge, over or under centrifugation
211
What should be added to tubes first, before adding reagent or patient cells?
Anti-sera/plasma
212
What is the general rule to resolve ABO discrepancies?
Check for technical/clerical errors, check patient transfusion history, repeat testing using a fresh cell suspension
213
What is the most common category of ABO discrepancy?
Unexpected Reverse Reactions
214
What is associated with category I ABO discrepancies?
Unexpected weakly reacting or missing reverse reactions
215
What can cause category I ABO discrepancies?
Patients with depressed ABO antibody production, certain disease states, immunosuppressive medication, BM or hematopoietic progenitor stem cell transplants
216
What is the significance of the K antigen?
The presence of the K antigen indicates that the person will not possess anti-K antibodies.
217
How are screening cells used to detect unexpected antibodies?
Patient plasma is mixed with commercial screening cells to identify the presence of unexpected antibodies.
218
What antigens should be included on screening cells for antibody detection?
The antigens expressed on screening cells should include: D, C, E, c, e, M, N, S, s, P1, Lea, Leb, K, k, Fya, Fyb, Jka, and Jkb.
219
What is the purpose of using group O cells in testing?
Group O cells are used because they do not react with ABO antibodies present in patient or donor plasma.
220
When should an antibody panel be performed?
An antibody panel should be performed when a new unexpected antibody is detected or when testing suggests a new antibody.
221
What is the purpose of crossmatch or compatibility testing?
Crossmatch or compatibility testing is used to determine compatibility between the patient and donor before transfusion.
222
When should phenotype testing be performed?
Phenotype testing should be performed when a patient has a previously identified antibody or when confirming a newly identified antibody.
223
What is the difference between phenotype and genotype testing?
Phenotype testing detects the physical expression of inherited traits, while genotype testing determines the genetic makeup.
