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Haemoglobin

Cyanmethaemoglbin (HICN)(Drabkin's method)


Haemoglobin or red pigment of RBSs is the main constituent of erythrocytes The main function of red blood cell Transfer of O2 from lungs to tissue Transfer of CO2 from tissue to lungs Each red cell has 640 million molecules of Hb .


Haemoglobin (Hb), protein constituting 1/3 of the red blood cells Synthesis begins in proerythroblast 65% at erythroblast stage 35% at reticulocyte stage Two parts Haem Globin


lt is a protein that transport oxygen and about 15% of the co2 in blood. Adult HB molecule of 4 haem attached to 2 and 2 globine chain. The essential component of Hb is the iron atom.

Alpha & beta chains

Synthesis of Haemoglobin (Hb)



Haem & globin produced at two different sites in the cells Haem in mitochondria Globin in polyribosomes

Synthesis of Haemoglobin

Clinical significance


Normal values for Hb are 140-200 g/L of blood in infants ,120-150 g/l in adult females and 140-165 g/L in adult males. When Hb value is below normal (less than 120g/L in F and less than 140 g/L IN M), the patient is said to be anaemic .in anaemic patient, concomitant measurement of Hb,(pcv), erythrocyte count (and from theses data ,calculation of the mean corpuscular volume MCV,and mean corpuscular Hb concentration MCHC) usually provide an important clue to the likely causes of anemia. Hb values higher than normal are found in polycythemia, erythrocytosis,and dehydration.

Principle

When whole blood sample is add to Drabkin's solution ,Hb (hemoglobin), Hi(met hemoglobin) and HBCO (carboxy- hemoglobin) are all oxidized to met hemoglobin by potassium ferricyanide. then the met hemoglobin is converted into the stable cyanmethaemoglobin is measured at 540 nm and compared with a certified cyanmethaemoglobin standard.

Specimen



The procedure requires 0.02 ml of whole blood venous blood should be mixed with an anticoagulant ,or blood may be taken from finger without use of anticoagulant .

0.01 ml

Whole blood sampled Mix well and allow to stand 15 min
2.5 ml
2.5 ml
Drabkin soluation
blank
test

procedure

Thank you





رفعت المحاضرة من قبل: Mohammed Basil Al-Taee
المشاهدات: لقد قام 19 عضواً و 362 زائراً بقراءة هذه المحاضرة








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