Week 3 Lab: Acid Hematin Flashcards
It is the red iron-bearing protein contained within the erythrocytes in normal blood.
Hemoglobin
Function of Hemoglobin?
It is the carrier of oxygen from the lungs to the tissue where it readily releases this oxygen to the tissues and then returns to the lungs to combine with more oxygen.
___ heme molecules are conjugated with ___ of globin chains.
4, 2 pairs
It represents the colored component.
Heme
It is a complex protein.
Globin
The molecular weight of one Hb molecule is?
64,458 daltons
Hemoglobin results are affected by the following factors?
- Age
- Sex
- Altitude of the locality
Methods for hemoglobin determination?
- Copper Sulfate or Specific Gravity Method
- Gasometric Method (Oxygen Capacity Method)
- Chemical Method (Iron Content Method)
- Colorimetric Methods (Visual, either Tallquist or Dare)
- Acid hematin (Sahlis Hellige, Haldene, Haden–Hausser, Newcomer, Sahli-adams, Osgood)
- Alkali Hematin (Clegg and King)
- Photoelectric (Oxyhemoglobin method, Cyanmethemoglobin or hemiglobincyanide/HiCN method)
The most common method for hemoglobin determination. This test has no numerical values for its result.
Copper Sulfate or Specific Gravity Method
A bright blue colored chemical is used for this test. After pricking the patient, wipe off the first drop of blood, then add a drop of blood to the mixture with this chemical.
Copper Sulfate or Specific Gravity Method
Results for Copper Sulfate or Specific Gravity Method?
If the blood drop floats: hemoglobin is low. If the blood drop sinks: hemoglobin is normal.
This test is used to determine iron in the blood.
Chemical Method (Iron Content Method)
Disadvantage of visual colorimetric methods?
The results are not standardized due to the different perceptions of the reader when it comes to the color produced.
Tallquist visual colorimetric uses?
filter paper, which absorbs the blood from the puncture site and is compared to the color comparison chart before it dries
Dare visual colorimetric uses?
capillary tube
The photoelectric methods use what instrument?
spectrophotometer
The best method for measuring plasma hemoglobin.
Oxyhemoglobin method
Composition of Oxyhemoglobin method?
20 ul blood + N/10 ammonia solution
The best method for hemoglobin determination considered by hematologist.
Cyanmethemoglobin or HiCN method
Composition of Cyanmethemoglobin or HiCN method?
Drabkin’s reagent + 20 ul blood
At what wavelength is the sample read for Cyanmethemoglobin or HiCN method?
540 nm
Hemoglobin determination test is used to?
- Screen for disease associated with anemia
- Determine the severity of anemia
- Follow the response to treatment for anemia
- Evaluate polycythemia
Increased hemoglobin is called?
hyperchromia
Decreased hemoglobin is called?
oligochromia
Increased (hyperchromia) is seen in?
- polycythemia
- dehydration
- in poorly compensated heart disease with cyanosis
- changing from high to low altitudes
Decreased (oligochromia) is seen in?
anemias
It is the presence of free hemoglobin in the plasma.
Hemoglobinemia
Hemoglobinemia is found in what conditions?
a. severe infection
b. severe burns
c. poisoning with potassium chlorate and mushroom
d. paroxysmal hemoglobinuria
e. HTR/hemolytic transfusion reaction
Specimen used for acid hematin?
Peripheral or unclotted venous blood
Instrument used for acid hematin method?
Hemoglobinometer
Principle of Acid Hematin Method?
Hemoglobin is converted to acid with dilute 0.1 N HCL and resulting brownish yellow color produced upon the addition of distilled water with the color standard in the comparator block.
Procedure for acid hematin method?
- Introduce 0.1 N HCL solution up to mark 2 of the Sahli graduated tube.
- Using the Sahli pipette, draw blood up to 20 ul.
- Dispense the measured volume of the blood into the graduated tube. Gently draw up and down to rinse the pipette.
- Thoroughly mix with the use of the stirrer and allow to stand for 5 minutes.
- Add distilled water drop by drop, stirring after each addition and compare with the comparator block.
- When the resulting solution compares with color standard in the comparator block, get the reading either from the grams or percentage.
Reagents used for acid hematin method?
0.1 N HCL solution and distilled water
Introduce 0.1 N HCL solution up to mark __ of the Sahli graduated tube.
2
In acid hematin, using the Sahli pipette, draw blood up to ___.
20 ul
Using the ________, draw blood up to 20 ul.
Sahli pipette
Thoroughly mix with the use of the stirrer and allow to stand for ___ minutes.
5
When the resulting solution compares with color standard in the comparator block, get the reading either from the _____ or _____.
grams or percentage.
The gram graduations of the Sahli graduated hemoglobin tube are in what intervals?
by 2 (2, 4, 6, … 22)
The percentage graduations of the Sahli graduated hemoglobin tube are in what intervals?
by 10 (10, 20, 30, … 140)
The gram graduations of the Sahli graduated hemoglobin tube are colored?
yellow
The percentage graduations of the Sahli graduated hemoglobin tube are colored?
orange
Reference ranges by the WHO for acid hematin method?
- Adult males: 13.0 - 17.0 gm/dl.
- Adult females (non-pregnant): 12.0 – 15.0 gm/dl.
- Adult females (pregnant): 11.0 - 14.0 gm/dl.
- Children, 6-12 years: 11.5 - 15.5 gm/dl.
- Children, 6 months to 6 years: 11.0 – 14.0 gm/dl.
- Children, 2 – 6 months: 9.5 – 14.0 gm/dl.
- At birth (full term): 13.6 – 19.6 gm/dl.
Critical values for acid hematin method?
- < 7 gm/dl (severe anemia)
- > 20 gm/dl (hyperviscosity)
What type of hemoglobin is not detected by acid hematin?
hemoglobin F
