Oct 23, 2010

Hemoglobin Estimation..clinical pathology

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;
  1. Sahli’s method..Outdated
  2. Cyanmet Hb method..Updated
  3. Spectrophotometer
  4. Haden Haussen method
Sahli’s Method of Hemoglobin Determination:
  • 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%.
  • 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:


medical procedures said...

thank you your post was really helpful to me

Naomi Mulwendo said...

great post but do you mind telling me how accurate the sahli method is??

Anonymous said...


Anonymous said...

Thanks alot

Sapan Anand said...


Aaditya Sharma said...

Can you tell me what exactly does the red % stand for? Please elaborate what is its use. Thanx

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