MIDTERM - HEMOGLOBIN METABOLISM Flashcards
(200 cards)
1
Q
iron bearing protein contained
within the erythrocytes .
A
hemoglobin
2
Q
hemoglobin comprises approximately ___% of the cytoplasmic
content of RBCs.
A
95
3
Q
one gram of hemoglobin can carry
____ of oxygen
A
1.34 ml
4
Q
The concentration of hemoglobin within RBCs is approximately ____ and its molecular weight is
approximately ____.
A
34 g/dL; 64,000 Daltons
5
Q
what are the main function of hemoglobin
A
transport oxygen from lungs to tissue, carbon dioxide from tissue to lungs.
contributes to acid-base balance by binding and releasing hydrogen ions and
transport nitric oxide (a regulator of vascular tone)
6
Q
a regulator of vascular tone
A
nitric oxide
7
Q
Hemoglobin is the first protein whose structure was described
using _____.
A
x-ray crystallography
8
Q
-
-
A
carbon, hydrogen, nitrogen
9
Q
the ring of heme composed of carbon, hydrogen, and nitrogen is called as
A
protoporphyrin IX
10
Q
what is the central atom found in the heme of the hemoglobin
A
divalent ferrous iron Fe2+
11
Q
The ferrous
iron in each heme molecule reversibly combines with how many
oxygen molecule.
A
oneone
12
Q
When the ferrous irons are oxidized
to the ferric state (Fe3+), they no longer can bind oxygen.
true or false
A
True
13
Q
is the binding of ferrous iron same with oxidizing ferrous iron to ferric state?
A
nope
When ferrous iron (Fe²⁺) binds oxygen, it is not oxidized — the bond is REVERSIBLE.
ganiyan ung way niya to hold oxygen and deliver to tissue
If it were oxidized to Fe³⁺, hemoglobin would become methemoglobin, which is functionally useless for oxygen transport.
14
Q
Oxidized hemoglobin is also called ___
A
methemoglobin
15
Q
describe the globin strcture
A
The four globin chains comprising each hemoglobin molecule
consist of two identical pairs of unlike polypeptide chains, 141 to
146 amino acids each.
16
Q
in globin structure, each globin chain is divided into how many helices and non helices
A
divided into eight helices separated by
seven nonhelical segments
17
Q
Hemoglobin is a tetramer of four globin chains with a heme attached
to each globin chain.
true or false
A
true
18
Q
globin chain alpha and its number of amino acids
A
141
19
Q
globin chain beta and its number of amino acids
A
146
20
Q
aside from globin chain alpha, what is the globin chain that has 141 amino acids as well?
A
globin chain zeta
21
Q
how many amino acids do theta has?
A
unknown
22
Q
the hemoglobin molecule can be describe as its
A
primary
secondary
tertiary
quaternary structures
23
Q
the structure of hemoglobin that refers to the amino acid sequence of the POLYPEPTIDE CHAINS
A
primary structure
24
Q
the structure of hemoglobin that refers to chain arrangements in HELICES and NON HELICES
A
secondary structure
25
the structure of hemoglobin that refers to the
arrangement of the helices into a PRETZEL LIKE CONFIGURATION
tertiary hemoglobin
26
The quaternary structure of hemoglobin, also called a _____, describes the complete hemoglobin molecule
tetramer
27
Globin chains loop to form a cleft pocket for heme. Each chain contains a heme group that is suspended between the__ and ___ helices of the polypeptide chain
E and F
28
The complete hemoglobin molecule is SPHERICAL, has four heme groups
attached to four polypeptide chains, and may carry up to
four molecules of oxygen
true or false
true
29
A small percentage of Hb A is ____.
glycated
30
is a posttranslational modification formed by the nonenzymatic
binding of various sugars to globin chain amino groups over
the life span of the RBC
glycation
31
explain glycation further
Hb A = the normal adult hemoglobin (α₂β₂).
Small percentage is glycated → a tiny fraction of hemoglobin molecules have sugar molecules stuck to them.
Glycation = attachment of sugar (usually glucose) to proteins.
Nonenzymatic = it happens spontaneously, without the help of enzymes.
Posttranslational = occurs after hemoglobin is already made (so not during synthesis).
Binding site = glucose attaches to the amino groups (especially the N-terminal valine of the β-chain).
Over RBC lifespan (120 days) = since RBCs circulate for ~4 months, the longer they’re in circulation and the higher the blood glucose, the more glycation accumulates.
32
The most characterized of the glycated
hemoglobins is
Hb A1c
33
The most characterized of the glycated
hemoglobins is Hb A1c, in which glucose attaches to the ____
N terminal valine of the b chain
34
Normally, about__ of
Hb A circulates in the A1c form.
4% to 6%
35
Heme biosynthesis occurs in the ____of bone marrow erythroid precursors,
mitochondria and cytoplasm
36
can mature rbc make hemoglobin?
nope, they will lose the capability to make as they lose mitochondria and ribosomes along the maturation process
37
how many enzymes do we have for heme synthesis
8
38
how many enzymes involve in hemem synthesis in both mitochondria and cytoplasm
each have 4 enzymes involve
39
the heme synthesis starts with the condensation of what substances
succinyl-coA and glycine
40
glycine and succinyl coenzyme A (CoA) is catalyzed by ___ to produced aminolevulinic acid (ALA)
aminolevulinate synthase
41
aminolevulinic acid (ALA)
--> in the cytoplasm, aminolevulinic acid dehydratase converts ALA to ___
porphobilinogen (PBG)
42
porphobilinogen (PBG)
--> it will then be converted into ______ through the enzyme ____
hydroxymethylbilane; hydroxymethylbilane synthase (PBG deaminase)
43
uroporphyrinogen III
-->will be converted into ____ through what enzyme
coproporphyrinogen III ; uroporphyrinogen III decarboxylase
44
hydroxymethylbilane
--> it will be converted into ___ through enzyme ____
uroporphyrinogen III; uroporphyrinogen III synthase
45
what are the products made along the heme synthesis under cytosol or cytoplasm?
porphobilinogen
hydroxymethylbilane
uroporphyrinogen III
coproporphyrinogen III
46
From coproporphyrinogen III, it will go back to mitochondria to continue and be converted into
protoporphyrinogen IX
47
coproporphyrinogen III will be converted into protoporphyrinogen IX through what enzyme
coproporphyrinogen III oxidase
48
protoporphyrinogen IX will be converted into ___ by the enzyme ____
protoporphyrin IX ; protoporphyrinogen oxidase
49
protoporphyrin IX will form a heme through what enzyme
ferrochelatase
50
where does the heme synthesis starts and ended?
mitochondria
51
in globin synthesis, which chromosome do alpha and zeta globin are coded?
short arm chromosome 16
52
in globin synthesis, which chromosome do epsilon, gamma, delta and beta globin gene cluster are coded?
short arm of chromosome 11
53
expect for which globin chain we do have a single genome per chromatid. In this 2 globin chain, they both have 2 copies per chromatid
alpha and gamma globins
54
Production of globin chains takes place in erythroid precursors from the PRONORMOBLAST through the circulating POLYCHROMATIC ERYTHROCYTES, but not in ____.
mature erythrocytes
55
Transcription of the globin genes to messenger ribonucleic acid (mRNA) occurs in the ___,
nucleus
56
Transcription of the globin genes to messenger ribonucleic acid (mRNA) occurs in the nucleus,
and translation of mRNA to the globin polypeptide chain occurs on ___
Ribosomes in the cytoplasm.
57
which globin chain produces more mRNA upon transcription? is it the alpha globin or the beta globin
alpha globin, but less efficient in translation
58
alpha globin makes more MRNA but the globin gene chain is much more efficient in translating,
Therefore, a and b chains are produced in
approximately _____ amounts. After translation is complete,
chains are released from the ribosomes in the cytoplasm.
equal
59
the alpha chain has what charge?
positive charge
60
b chain has what charge?
negative
61
arrange the highest affinity of a chain starting alpha
alpha chain
gamma chain
delta chain
62
each globin chain binds to a
heme molecule, then forms a
heterodimer
63
if each globin chain binds to a heme molecule, then forms a heterodimer, then how come a 2 heterodimer form a tetramer
kasi heterodimer means (1heme)alpha-beta (1 heme)dimer
so doblehin un tetra na
64
in order to form a complete hemoglobin mob\lecule
Two heterodimers then combine
to form a ____.
tetramer
65
the alpha chain has a positive charge and has the highest affinity for what chain
b chain because of its negative charge
66
The two alpha and two beta chain will form ____ the major hemoglobin present from 6 months of age through adult hood
HB A
67
chains comprising the HB A2
Two alpha and two delta
68
Hb A2 comprises less
than ___ of total hemoglobin in adults.
3.5%
69
Hb F contains ___ chains.
two alpha and two gamma
70
In healthy adults, Hb F comprises ___
of total hemoglobin, and it is present only in a small proportion
of the RBCs (uneven distribution).
1% to 2%
71
These RBCs with Hb F are
called F or ___
A/F cells.
72
A third function of
hemoglobin involves the
___, ___- and ____ of nitric oxide.
binding, inactivation, and
transport
73
Nitric oxide is secreted by
___
vascular endothelial cells
74
Nitric oxide is secreted by
vascular endothelial cells
and causes ___
relaxation of
vascular wall smooth
muscle and vasodilation
75
The function of hemoglobin
is to readily bind oxygen
molecules in the lung,
which requires ____ oxygen
affinity; to transport
oxygen;
high
76
hemoglobin transport and efficiently
unload oxygen to the
tissues, which requires ___oxygen affinity
low
77
is the ability of hemoglobin to bind or
release oxygen
oxygen affinity
78
The relationship between OXYGEN tension and HEMOGLOBIN SATURATION with oxygen is described as
Oxygen dissociation curve
79
it states the relationship of oxygen affinity with hemoglobin to PH
bohr effect
80
In Bohr effect, if the pH increase or the blood is alkaline (alkalosis) the affinity of hemoglobin to oxygen will
(increase. decrease)
increase affinity
81
In Bohr effect, if the pH decrease or the blood is acidic (acidosis) the affinity of hemoglobin to oxygen will
(increase. decrease)
decrease affinity
acidosis means mataas si CO2
- more CO₂ means more H⁺, and that indirectly pushes Hb to let go of O₂.
82
increase temperature
shift to the right
kunwari may lagnat o kaya may activity, the body needs more oxygen to keep up. So low affinity shift to the right, more oxygen delivered
83
decrease temperature
shift to the left
malamig, in r state si hemoglobin
di need ni katawan ng oxygen, keep muna ni hemoglobin
high affinity
84
increase organic phosphate (2,3 DPG)
shift to the right
2,3 DPG) stabilizes the T state - tense - low affinity
85
decrease organic phosphate (2,3 DPG)
shift to the left
2,3 dpg promotes release of oxygen, low 2,3 high affinity
86
increase p(CO2)
shift to the right
87
decrease p(CO2)
shift to the left
88
increase p(CO)
shift to the left
epal kasi to, nakikiagaw. Mas less ung delivery ng oxygen to tissue
89
decrease p(CO)
shift to the right
90
increase pH
shift to the left
91
decrease pH
shift to the right
92
The normal position of curve depends on
§ Concentration of 2,3-DPG
§ H+ ion concentration (pH)
§ CO2 in red blood cells
§ Structure of Hb
93
HbS will shft to ??
shift to the right
may sira kasi yan eh, kaya di makakahwak ng maayos sa oxygen
94
HbF will shift to the
shift to the left
This left shift allows the fetus to “steal” O₂ from maternal blood across the placenta.
it has weak binding ability to 2,3 BPG, and si bpg is promoter ng oxygen release (T state)
95
Myoglobin, a muscle protein, produces a
markedly ____ curve indicating a very ___oxygen affinity.
left-shifted; high
It is not effective in releasing oxygen at physiologic oxygen tensions.
96
the normal partial pressure of Oxygen to achive a 50% oxygen saturation of a hemoglobin
27 mm Hg
97
explain why a shift to the left curve will takes less than 27 mmhg pO2
hgb has high affinity to oxygen
it does not need a lot of oxygen for it to reach the 50% faster
Hb is stickier → grabs O₂ quickly, even when O₂ levels are low.
→ So at lower PO₂, Hb already reaches 50% saturation.
98
explain why a shift to the right curve will takes more than 27 mmhg pO2
low affinity kasi si right shift
nabibitawan si oxygen, it needs more PO2, higher than 27 mmHg to reach 50% even though there's plenty of oxygen available
99
A shift in the curve because of a change in pH
(or hydrogen ion concentration) is termed the
Bohr effect
100
Hb F (fetal hemoglobin, the primary hemoglobin in newborns)
has a P50 of ___mm Hg, which results in a left shift
of the oxygen dissociation curve and increased affinity for oxygen
relative to that of Hb A.
19 to 21
101
what are the physiological forms of hemoglobin
oxyhemoglobin
Deoxyhemoglobin
102
hemoglobin in combination WITH
oxygen gives pinkness to the skin and mucous membrane.
seen in arterial circulation
oxyhemoglobin
103
hgb with iron but no O2, seen in
venous circulation. Unassociated with oxygen
deoxyhemoglobin
104
a hemoglobin that is Found in normal human embryos
and fetuses with a gestational age
of less than three months
Embryonic Hemoglobin
105
this hemoglobin is absent at birth
Embryonic Hemoglobin
106
what are the hemoglobin under embryonic hemoglobin
gower I, gower II, and portland
107
in hemoglobin Gower I, what are the globin chains involved
2 zeta 2 epsilon
108
what are the globin chains involved in Gower II
2 alpha and 2 epsilon
109
what are the globin chains involved in portland
2 zeta and 2 gamma
110
the major hemoglobin of the fetus
and newborns
fetal hemoglobin
111
fetal hemoglobin is composed of what globin chains
2 alpha and 2 gamma
112
when was the fetal hemoglobin produced?
4 months after conception
113
normal ADULT hemoglobin
hemoglobin A or A1
114
how many percent of hemoglobin in a normal adult does HbA produced after one year onwards
95 - 97%
115
Hemoglobin A or A1 is composed of what globin chains?
2 alpha 2 beta (141, 146)
116
How many percent do Hemoglobin A2 constitute in the total hemoglobin?
less than 3%
117
Hemoglobin A has the globin chains of
2 alpha 2 delta
118
a normal hemoglobin that is a product of a degradation of HbA2
Hemoglobin 3
119
Hemoglobin 3 has what globin chains?
2 alpha 2 delta - same with HbA2 as it's own degradation
120
This is the primary hemoglobin
in people with sickle cell disease
Hemoglobin S
121
what is wrong in terms of the globin chains of blood with sickle cell disease?
2 normal alpha
2 abnormal beta
122
causes the red blood cell to deform and
assume a sickle shape when exposed to
decreased amounts of oxygen.
Hemoglobin S
123
In hemoglobin S, the Glutamic acid in the 6th position of beta chain place was been replaced by ____
Valine
124
In an abnormal hemoglobin, ____ patient with this kind of hemoglobin only has one copy of normal Beta chain and one beta HbC chain
Hemoglobin C
125
In hemoglobin C, the Glutamic acid in the 6th position of beta chain place was been replaced by ____
Lysine
126
an abnormal hemoglobin that usually causes a minor amount of hemolytic anemia and a mild to moderate enlargement of the spleen.
Hemoglobin C
127
is one of the most common beta chain
hemoglobin variants in the world.
Hemoglobin E
128
Hemoglobin C trait (HbAC) occurs in about 2–3% of individuals of
West African descent but they are hetorozygotes
129
130
___ is termed as silent killer for its colorless gas , odor and patient becomes easily hypoxic.
Carbon monoxide
131
In hemoglobin C, instead of glutamic acid , ___ is in B6
lysine
132
It usually causes a minor amount of hemolytic
anemia and a mild to moderate
enlargement of the spleen
hemoglobin C
133
is one of the most common beta
chain hemoglobin variants in the world.
Hemoglobin E
134
People who are homozygous for Hb E (have two
copies of βE) generally have a ____
mild hemolytic
anemia, microcytic red blood cells, and a mild
enlargement of the spleen.
135
Hemoglobin E
Substitution of glutamic acid to lysine on
___ position of beta chain
26th
136
an abnormal hemoglobin that occurs in some cases of
alpha thalassemia .
hemoglobin H
137
hemoglobin H has what globin chains
4 beta and is response to a sever shortage of alpha chains
138
this kind of hemoglobin gene does not
cause symptoms unless it is combined with another
mutation, such as the one for beta thalassemia
trait
true
139
Are acquired hemoglobin variants whose structure has
been modified by drugs or environmental chemicals.
CHEMICALLY MODIFIED
HEMOGLOBINS
140
inability to transport oxygen to the tissue well resulting in
cyanosis
141
3 types of chemically modified hemoglobins
methemoglobin
sulfhemoglobin
carboxyhemoglobin
142
* Is a form hgb in its ferric state
methemoglobin
143
methemoglobin reduction
systems, predominantly the ____pathway, normally limit
its accumulation to only 1% of total hemoglobin
NADH-cytochrome b5 reductase 3 (NADH-methemoglobin reductase)
144
blood has a chocolate brown color and does not revert to
red on exposure to oxygen
methemoglobin
145
Individuals with methemoglobin levels less than 25% , give the symptoms
asymptomatic
146
If the methemoglobin level increases to more than ______% of total hemoglobin, `cyanosis` (bluish discoloration of skin and
mucous membranes) and symptoms of `hypoxia` (dyspnea,
headache, vertigo, change in mental status) occur
30
147
Levels of methemoglobin greater than ______% can lead to coma and death
50
148
explain how to treat the methemoglobinemia
withdrawals of the offiending oxidant is sufficient for the recovery, basta istop lang si oxidant
however, if the toxicity reaches 30% or more, intravenous methylene blue is administered
149
how methylene blue helps cure methemoglobinemia
Methylene blue `reduces`
methemoglobin ferric iron to the ferrous state through
NADPH-methemoglobin reductase and NADPH produced by
glucose-6-phosphate dehydrogenase in the hexose monophosphate
shunt
1. reduce the ferric irons back to ferrous
2. NADPH product frbrom hexose monophosphate shunt
150
In life-threatening cases of methemoglobinemia, ___ may be required
exchange
transfusion
151
The acquired form, also called
`toxic methemoglobinemia, occurs in normal individuals after
exposure to an exogenous oxidant, such as ____
nitrites,
primaquine,
dapsone, or
benzocaine
152
methemoglobin is Peak in the range of ___ nm at pH ____ under
spectral absorption test.
630 – 640; 7.1
153
what are the causes of methemoglobin
acquired and hereditary
154
Hereditary causes of methemoglobinemia are rare and include
mutations in the gene for _______), resulting in a diminished capacity to reduce
methemoglobin, and mutations in the ______ gene,
resulting in a structurally abnormal polypeptide chain that
favors the oxidized ferric form of iron and prevents its reduction.
NADH-cytochrome b5 reductase
3 (CYB5R3)
a-, b-, or g-globin
155
____ testing are used for identification
of Hb M variants.
Hemoglobin electrophoresis,
HPLC, and DNA mutation
156
is inherited
in an autosomal dominant pattern, with methemoglobin comprising
30% to 50% of total hemoglobin
Hb M
157
There is no effective
treatment for this form of methemoglobinemia.
Hb M
158
Cytochrome b5 reductase deficiency is an autosomal __________ disorder, and
methemoglobin elevations occur in individuals who are homozygous
or compound heterozygous for a CYB5R3 mutation
recessive
159
state of recessive or dominant disorder
hereditary methemoglobinemia
CYB5R3 deficiency -
a,b, y globin chain mutation -
CYB5R3 deficiency - recessive
a,b, y globin chain mutation - dominant
160
Formed by the irreversible oxidation of Hb of certain drugs and
chemicals.
SULFHEMOGLOBIN
161
examples of drugs causing sulfhemoglobin
sulfanilamides,
phenacetin,
nitrites, and
phenylhydrazine
162
exposure to sulfur chemicals in industrial
or environmental settings can cause ____
sulfhemoglobin
163
In sulfhemoglobin, what is added on the hemoglobin and the resulting color?
hydrogen sulfide; greenish color
book:
It is formed by the addition of
a sulfur atom to the pyrrole ring of heme and has a greenish
pigment
164
treatment of sulfhemoglobin
Treatment consists of prevention by
avoidance of the offending agent.
Sulfhemoglobin
cannot be converted to normal Hb A; it persists
for the life of the cell.
si sulfhemoglobin is like your ex na kahit anong gawin mo hindi na babalik , kahit kumanta ka pa ng "nandito ako" rendition by rob deniele
165
If sulfhemoglobin reaches the critical level in the blood it
imparts the color
MAUVE LAVENDER
166
sulfhemoglobin and methemoglobin has the similar peak spectral measurement.
to determine:
The sulfhemoglobin spectral
curve, however, does not shift when ___ is added, a feature
that distinguishes it from methemoglobin.
cyanide
167
how sulfhemoglobin is reported?
1. Px under prolonged treatment with sulfonamides or aromatic compounds (phenacitin, acetanilide )
* 2. Px with severe constipation
* 3. In cases of bacteremia caused by Clostridium perfringens
* 4. In condition known as enterogenous cyanosis
168
Results from the binding of carbon monoxide to heme iron
CARBOXYHEMOGLOBIN
169
Hb can combine with carbon monoxide with affinity ____times greater than that of Oxygen.
book:
240 times
170
___ is termed as silent killer for its colorless gas , odor and patient becomes easily hypoxic.
Carbon monoxide
171
Some carboxyhemoglobin is produced endogenously, but it
normally comprises less than
____% of total hemoglobin
2
172
Carboxyhemoglobin may be detected by spectral absorption
instruments at __nm
540
173
carboxyhemoglobin
It gives blood a ___,
which is sometimes imparted to the skin of victims
cherry red color
174
A diagnosis
of carbon monoxide poisoning is made if the COHb level is
greater than ____% in nonsmokers and greater than ____% in smokers.
3% ; 10%
175
Treatment involves removing the carbon monoxide source
and administration of ____
100% oxygen
176
methods to detect or determine hemoglobin
visual methods
gasometric method
spectronic method
automated
other method such as alkaline, specific gravity, comparator
177
qualitative screening test based on
specific gravity. The density of the
drop of blood is directly proportional to
the amount of hemoglobin it contains.
copper sulfate specific gravty
178
what are the visual method to determine hgb
A. Sahli Method
B .Dares Method
c. Hadens Method
D.Wintrobe
E.Haldene
F.Tallquists
179
The principle of the test is that when
the drop of donor's blood dropped into
copper sulfate solution becomes
encased in a sac of
copper proteinate, which prevents any
change in the specific gravity for
about 15 seconds.
copper sulfate specific gravity
180
Hb will combine and liberate a fixed quantity of O₂.
Gasometric Method (Oxygen Capacity
Method)
181
In Gasometric Method (Oxygen Capacity
Method), the blood will be hemolyzed using ___ and the gas is collected and measured in a van slyke apparatus
saponin
182
a colorimetric methods under visiual
direct matching
acid hematin
alkaline hematin
183
a colorimetric methods under photoelectric
1.Oxyhemoglobin Method-
2. Cyanmethemoglobin or HiCN
method
184
a colorimetric - photoeelectric method that measures plasma hemoglobin
oxyhemoglobin method
185
a colorimetric - photoeelectric method that is a -standard and reference method use
to measure hemoglobin
cyanmethemoglobin or HiCN method
186
what are the factors that can affect hemoglobin results
age
sex
altitude of the locality
187
reagents used in cyanmet
Modified drabkin’s reagent
188
modified drabkin's reagent color and pH
- pale and yellow with a pH of 7.2 +
0.2
189
composition of modified drabkin's reagent
Sodium bicarbonate
1 gram
Potassium cyanide
52 mg
Potassium ferricyanide
198 mg
Distilled water
1000 mL
190
(HYPERCHROMIA)increased hemoglobin level
found in:
a. polycythemia
b. dehydration
c. changing from high to low altitudes
191
(oligochromia) decreased hemoglobin
level
found in:
anemia
192
Drabkin’s reagent is sensitive to
light
to correct it
Store in a brown bottle or in a
dark place
193
2. WBC Count (>20 x 10 ⁹/L)
Platelet Count (>700 x 10⁹/L)- can cause turbidity and
a falsely high
result
to correct it
Centrifuge the solution and
measure the supernatant
194
Lipemic sample can interfere
and can give a false result
to correct it
Add 0.01 mL of the patient’s
plasma to 5 mL of drabkin’s
reagent and used the solution as
reagent blank
195
Hb S and Hb C maybe resistant
to hemolysis causing turbidity
to correct it
Dilution with distilled water (1:2)
196
. Abnormal globulins found in
multiple myeloma or
Waldenstrom macroglobulinemia
may precipitate
to correct it
Add 0.1 g of potassium
carbonate to drabkin’s reagent
197
The hemoglobin determination test is used to
1. Screen for disease associated with anemia
2. Determine tThe cyanmethemoglobin method is the reference method for hemoglobin
assayhe severity of anemia
3. Follow the response to treatment for anemia
4. Evaluate polycythemia
198
principle of cyanmethemoglobin assay
Free hemoglobin combines
with potassium ferricyanide contained in the cyanmethemoglobin
reagent, which converts hemoglobin iron from the ferrous to the
ferric state to form methemoglobin. Methemoglobin combines
with potassium cyanide to form the stable pigment cyanmethemoglobin.
T
199
The cyanmethemoglobin color intensity, which is proportional
to hemoglobin concentration, is measured at __ nm spectrophotometrically
and compared with a standard
540
200
Many instruments now use ___to
convert hemoglobin to SLS-methemoglobin. This method does
not generate toxic wastes
sodium lauryl sulfate (SLS)
