1. Estimation of Hemoglobin Content.

2. Haemoglobin:
-It is a chromoprotien of M.W
-It is globular in shape.
-It represents 34 % of RBCs volume.
-It is made up of 4 subunits each of which is made up of Haem molecule conjugated to a polypeptide chain.

3. Sahli' s Method for Estimation Of Haemoglobin:
Principle :
- This method depends on converting Hb. Into acid haematin ( has a dark brown colour ).
- The solution developed is diluted with water and the colour developed after dilution is matched with the colour of the standard tubes.

4. Reagents and equipments :
- Sahli apparatus ( Haemoglobinometer ) consists of :
A- Central graduated tube that have two graduations; one indicating the amount of Hb. In gm ∕ 100cc ,while the other indicating the percentage.
B- Two standard tubes on its sides.
- Special pipette : of 0.02 ml capacity.
- N∕10 Hcl solution& Distilled water.
- Dropper & Glass rods .

7. Procedure :
1- Take N∕10 Hcl up to the mark 20 % in the graduated tube with the help of dropper.
2- Withdraw a blood by the pipette up to the mark of 0.02 ml. without air entry inbetween blood column.
3- Wipe the tip of the pipette of any blood and gently blow this blood into the graduated tube containing N∕10 Hcl.
4- Mix the blood with Hcl several times.

8. 5- Allow tube to stand for 10 minutes so that Hb is converted to acid haematin.
6- Add distilled water drop by dop and mix well with aglass rod.
7- continue this process till the colour of the contents of the central tube is the same as in the standard tubes.
8- Record your results by noting the level of diluted blood graduated tube which indicates the percentage of Hb. And grams of Hb.∕100cc. blood.

9. Normal Values : - Adult male: 14 – 16 gm %( average15 gm%)
- Adult female : 12 – 15 gm % ( average 13 gm % )
- Newly Born infant: 18 gm %
- children: 12 gm %

10. Clinical significance Of Hb estimation :
1- Diagnosis of :
▪ Anaemia ( if Hb. Is less than normal values )
Polycythaemia ( if Hb. Is more than normal values ) ▪
2- Calculation of some blood indices as:
▪ Mean Corpuscular Hb. ( MCH )
▪ Mean Corpuscular Hb. Concentration ( MCHC )