THE ESTIMATON OF HAEMOGLOBIN COCENTRATION

THE ESTIMATON OF HAEMOGLOBIN COCENTRATION
Aim:- to measure the amount of hemoglobin (Hb) present in 100 milliliter of blood. The result is expressed in gm/dl.
Methods for estimation of haemoglobin as follows:
I- Cyanmethaemoglobin method.
II- Sahli s acid haematin method.
Sahli s acid haematin
Hb is converted into acid haematian by hydrochloric acid. The brown color of the compound is matched against a brown glass standard in a comparator.
Apparatus
Sahli-type haemoglobinometer consisting of the comparator with glass standards , a square Hb tube marked both in grams and percentage figures and Hb pipette marked at 20 microliter , 0.1 N HCL and distilled water
Procedure
1) Fill the Hb caliberated tube up to the mark 20 (not less) with 0.1N HCL by means of a dropper.
2) Fill the Hb pipette exactly up to 20 microliter mark by gentle controlled sucking; the pipette is held horizontally while taking the blood .If a slight excess is drawn in, it may be removed by touching the point of the pipette with the finger or gauze. If a great excess has been drawn in, inaccuracy will result, in this case the pipette must be cleaned, dried and refilled. Wipe off with gauze the blood on the outside of the pipette.
3) Empty the pipette into acid in the tube by keeping the point of the pipette to the bottom of the tube and gently blowing off the blood without causing bubbles. Rinse the pipette at least three times by drawing in and discharging the blood acid mixture.
4) Mix the acid haematin solution in the tube with the glass rod and allow the tube to stand for 10 minutes. In this interval at least 95 percent of the colour of acid haematin is developed.
5) Now dilute the solution of acid haematin by adding distilled water, drop by drop, stirring the mixure all the time with glass rod. The comparator is held against good daylight and the addition of water continued till the colour of solution matches perfectly with that of the standards. Take the reading in grams percent. The bottom of the meniscus is read.
Normal range
Hb = 14-18 mg/dl in male and 13-16 mg/dl in female.
Clinical correlation:-
Anemia
Anemia means deficiency of hemoglobin in the blood, which can be caused by either too few red blood cells or too little hemoglobin in the cells. Some types of anemia and their physiologic causes are the following.
Blood Loss Anemia (hemorrhage)
Aplastic Anemia Bone marrow aplasia means lack of functioning bone marrow. For instance, a person exposed to gamma ray radiation from a nuclear bomb blast.
Hemolytic Anemia Different abnormalities of the red blood cells, many of which are hereditarily acquired, make the cells fragile, so that they rupture easily as they go through the capillaries, especially through the spleen.
POLYCYTHEMIA
Is increase number of RBC in the peripheral blood & not increase in Hb concentration in the RBC. There are 2 types of polycythemia:- a- primary or polcythemia rubra vera and b- secondary to smocking or high altitude.