deck_3529203 Flashcards
locus
location of the gene on the chromosome
allele
one of two or more different genes that may occupy a specific locus on a chromosome
homozygous
having two identical alleles for a given gene
heterozygous
having two different alleles for a given gene
dominant
a gene that is always expressed wether it is present in the homo or heterozygous state
recessive
a gene that is expressed only when it is in the homozygous state
co-dominant (egalitarian)
both alleles are expressed in the heterozygous sate (AB blood)
amorph or silent allele
a gene that produces no products even in homozygous state
phenotype
the detectable products of genes only discovered through the description of observed traits or the result of direct testing (physical trait)
genotype
total sum of genes present on the chromosomes with the respect to the one or more characteristics, regardless of wether or not they produce detectable products
zeta potential
decrease in the electrical charge of RBC when it is suspended in a high ionic strength colloidal medium (albumin) also decreases the repulsion of the RBC
what is the “job” of IgG and IgM in terms of bridging the gap between RBC?
IgM bridges the gap easier because they are larger than IgG
what is the temp reactivity of IgG and IgM?
G- 30-37CM- 4-27C
what is the effect of LISS in the Ag-Ab reaction?
the addition of LISS will help the rate of association between antigen and antibody. the rate is increased by lowering the ionic strength.
what are the 4 enzymes used in blood bank?
ficinpapaintrypsinbromelin
AHG effects and what does it do?
useful in detecting IgG and complement
what is dosage?
homozygous gives stronger reactions then heterozygous
what its he genotype and phenotype of bombay?
Oh- phenotypehh- genotype
which precursor type substance for ABH antigens?
type 2
name the two stages of RBC agglutination in correct order of sequence
1)sensitization2) clumping (agglutination)
the reverse or backside test detects the presence or absence of?
antibodies using the patient’s serum/plasma
the forward test detects?
antigens on the patients RBC using antisera
does lewis cause HDN? why?
no, because it cannot cross the placenta and because it is not fully developed in a newborn
what antibodies most often cause HDN?
Rh
what are you called if you have no Rh antigens?
Rh null
T/F lewis antibodies are enhanced by enzymes
true
T/F lewis antigens ten to become stronger during pregnancy
false- they become weaker
T/F lewis antibodies usually occur without known RBC stimulus
true
T/F the lewis system includes soluble antigens that are present in saliva and plasma with antigenic determinants occurring naturally on the RBC surface
false - they are made in the tissue and are not on the RBC surface
T/F lewis antibodies commonly cause HDN and HTR
false - they cannot cross the placenta and they will convert in a transfusion
T/F the Rh system was the first to be discovered and by far the most significant for transfusion practice
false- the ABO was the first to be discovered and is most significant for the transfusion
T/F Rh Abs react more strongly at 4C than at 37C
false- IgG likes 37
T/F Rh Abs can pass the placenta
true
T/F Rh Abs are not a frequent cause of HDN
false
where would we find anti-A1?
A2BA3AxA2
where would you see mixed field agglutination with Anti-A?
A3
what % of caucasians are secretors?
80%
where would you find anti-AB antiserum?
O blood type
anti-C antiserum will react with an individual with type ?
R1R2 (DCe/DcE)r ry (dce/dCE)Rz r ( DCE/dce)r’r” (dCe/dcE)any “"”C””””
when would you do a weak D testing?
if the initial spin is negative for a donor
what would be a good indication of HDN testing?
DAT - ( if + do an elution and antibody ID)
what is dolichos biflorus?
an anti-A1 lectin used to confirm the antigens on RBC
who is a good candidate for Rho-gam?
Rh- negative mothers who deliver Rh+ babies
list the H substance demonstrated in order of decreasing reactivity
O>A2>B>A2B>A1>A1B
what is landsteiner’s rule?
Ab are present in plasma only when the corresponding Ag is not present on the RBC
why are cord cells washed?
to remove Wharton’s jelly (Wharton’s jelly may cause agglutination and false +)
secretor status test used for H substance
inhibition and neutralization tests
why is Anti-AB antiserum used in the lab?
detections of subgroups of A weaker than A2
be able to pick mothers and babies who would get Rhogam
mother is negative baby is positive
convert Fisher-Race and Wiener . know how to use this chart interchangably
R/r to CDER determines D. R=D r=dR1/r’ = CeR2/r’’ = cERo/r = ceRz/ ry = CE
if you have two parents that are A1/A1 and A1/A2 what is the phenotype of their offspring?
A
if you have MM and MN, which agglutinates more strongly? why?
MM due to the dosage effect. it affects more strongly in the homozygous state
will time have an effect on antigen/antibody reaction?
yes
will over centrifugation cause a false negative in an anitgen/antibody reaction?
no- it is more likely to give a false positive
is a reaction at 4C clinically significant?
no
if you decrease serum:cell ratio does it provide more antibody molecules to the antigen sites available for reaction?
no
are lewis antibodies clinically significant?
no
can non secretors secrete ABO substances regardless of ABO group?
no
Name two substances that can reduce the zeta potential and allow RBC to approach each other more closely and be agglutinated
albumin LISS
name two other influencing factors in Ag-Ab reactions
temp.pHcentrifugationamount of timeAg:Abconcentrationionic strengthdosage
the ___ gene is necessary for the expression of the ABO genes
H
Ulex europeaus is a lectin with __ specificity, whereas Dolichos biflorus is a lectin with ___ specificity
Anti-H and Anti-A
List the three genotypes that produce the A1 phenotype
A1A1A1A2A1O
list the possible genotypes and phenotypes from a mating of AB and BO individuals
ABBAO
individuals that do not inherit the H gene have the genotype ___ and are said to have the __ phenotype; they also possess an additional Ab, ___ , in comparison to normal O individuals
hh, bombay, anti-H
what is the Rh negative genotype
dd
For rh antibodies which is true?-react better at 37C then 4C-cross the placenta-frequently cause HDN
all are true
if you had the following blood types, which would cause a mixed-field agglutination?ABA1A3AxO
A3
do some A2 individuals produce anti-A1?
yes- 8%
if you had the following blood types, which would react with anti-C?DcedceDcE/DcEdCe
dCe
which is the least useful for studying HDN-elution and antibody ID-serum billirubin-direct antiglobulin-cord blood hemoglobinsecretor testing
secretor testing
where is the purpose of the Rh immune globulin?
to prevent sensitization of the Rh negative mother to the baby’s Rh positive blood
to truly designate Rh negative:
Blood will not react with Anti-Dproceed to weak D testing
which would be useful in detecting secretor status for H substance?- A1 lectin-boiled saliva-ulex europaeus extract-A cells- O cells
boiled salivaulex europaeus extractO cells
if a mother is D = and Dw = and a father is homozygous for D antigen, what will their offspring’s genotype be?
100 % Dd
what causes HDN to occur?
maternal cells lack antigen that fetal cells have. that is what causes sensitization
reverse ABO grouping is inadequate to…
newborns
name the antiseras used in detecting Rh
anti-Danti-Canti-Eanti-canti-e
another name for the F antigen is
compound antigen
what is present when F antigen is expressed on the RBC
c and e inherited on the same haplotype
which will react with anti-F?DCeDcEDcedCedcF
Dce
with R1R1 individuals (DCe/DCe) if given dce, what antibody will most likely form?
anti-c
which blood group reacts most strongly with anti-H lectin? (ulex europaeus)
group O
r
dce
r’
dCe
r’’
dcE
ry
dCE
R’
DCe
R’’
DcE
Ro
Dce
Rz
DCE
what are the Rh genes in order of frequency in caucasians?
most frequent: R’- DCe2nd: r-dce3rd:R’‘-DcEleast frequent: ry- dCE
what are good indications of HDN?
bilirubinDAThemoglobin
