Estimation of Hemoglobin Content Haemoglobin It is a
Estimation of Hemoglobin Content.
Haemoglobin: -It is a chromoprotien of M. W. 64450. -It is globular in shape. volume. -It represents 34 % of RBCs -It is made up of 4 subunits each of which is made up of Haem molecule conjugated to a polypeptide chain.
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.
Reagents and equipments : - Sahli apparatus ( Haemoglobinometer ) consists of : A- Central graduated tube that have two graduations; one indicating the amount of Hb. In gm ∕ 100 cc , 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.
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.
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 duated tube which indicates the percentage of Hb. And grams of Hb. ∕ 100 cc. blood.
Normal Values : - Adult male: 14 – 16 gm %( average 15 gm%) - Adult female : 12 – 15 gm % ( average 13 gm % ) - Newly Born infant: 18 gm % - children: 12 gm %
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 )
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