Hemoglobin is a protein present in RBCs for exchange of
gases with tissues. Blood is a specialized type of
connective tissue in the form of fluid. It has two components called as plasma
and cells.
- Plasma
contains 12 coagulation factors. Serum is
formed by the removal of these coagulation factors. Serum is collected in
red color vacuotainer. It does not let the blood clot.
- The
ratio of cells in the blood is RBCs, WBCs and Platelets as 500:1:30 respectively.
There are four methods for the determination of hemoglobin
in the blood;
- Sahli’s
method..Outdated
- Cyanmet
Hb method..Updated
- Spectrophotometer
- Haden
Haussen method
Sahli’s Method of Hemoglobin Determination:
Apparatus:
- Sahli’s
tube which is having red and yellow scales on two sides. Red scale is
percentage scale and yellow scale is gram percentage or g/100ml scale.
- Heamometer
which is having two standards.
- Sahli’s
pipette.
- Error
percentage is 3%.
Procedure:
- In
sahli’s tube, take N/10 HCL(1/10th of the original HCL) up
to 10th level of scale.
- In
sahli’s pipette, take 0.02ml(20microleter) blood.
- Add
blood from pipette into tube.
- HCL
will cause the lysis of the blood cells and hemoglobin is released.
- Hb
after combining with HCL, forms acid hematin which is of
tan color.
- Put
tube in the hemometer and continuously add drops of distilled water and
shake with the stirrer until color matches. Then, take the reading.
Interpretation of the results:
Heam portion of hemoglobin is a porphyrin type pigment
and contains iron.
Types of Hemoglobin:
Heam Cycle: