Practical work #5. Method of definition of hemoglobin level in blood (Sali’s method)
Sali method is used for the definition of the hemoglobin amount in blood.
Principle of this method is the following. After adding hydrochloric acid hemoglobin transforms into hydrochloric hematin that has brown color, intensity of which is straightly proportional to the hemoglobin content. The solution of hydrochloric hematin is diluted with water till it gets standard color.
This method of the definition of hemoglobin amount gives results with accuracy to 10%. Mistake is associated with the technical problems during definition and possible subjective mistakes in the definition of color. But this method is widely spread because it is easy and simple.
Hemometer Sali is used for this definition. It is a holder with 3 test-tubes. There is 1% solution of hydrochloric hematin. Middle tube has marks from 0 to 23•10 g/l and it is for the definition of hemoglobin in the examined blood.
Normally, the amount of hemoglobin in men is 140-160 g/l, in women – 120-140 g/l.
Figure 6.4 – Hemometer Sali; a – tubes with standard solution of muriatic hematin; b – tube for the definition of hemoglobin
Objectives: to define and estimate the amount of hemoglobin in the examined blood.
Requirements for work: hemometer Sali, pipette, glass stick, 0,1N solution of hydrochloric acid, distillated water, 96% ethanol, cotton wool.
With the help of pipette put 0,1N solution of hydrochloric acid into the middle tube of hemometer till the lowest mark (0,2 ml);
For the definition of hemoglobin put blood into the capillary till the mark (0,02 ml);
Clean the opening of the capillary with cotton wool;
Put the capillary into the tube with acid and carefully eject the blood from the capillary to the bottom of the tube;
Without taking out the capillary from the tube, clean it with acid from the upper layers;
Mix blood with acid by shaking the tube;
Put the tube into the hemometer;
Leave hemometer for 4-5 minutes. By this time acid will ruin erythrocyte membrane, transform hemoglobin into hydrochloric hematin that has brown color;
Put distillated water into the middle tube, until the color of the solution in the middle tube will become the same color with the one in standard tubes;
Fix the level of solution in the middle tube by the lower meniscus;
To get the value in g/l, the value in g% should be multiplied by 10.
Recommendations for writing down the results:
Draw down hemometer of Sali.
Calculate the amount of hemoglobin in the examined blood. Write down the results in the absolute units.
For example:
Hemometer has graduations in absolute units of hemoglobin.
Result – 15 g%
Calculating: 15 g% • 10 = 150 g/l.
Answer following questions in conclusion:
Is the amount of hemoglobin normal in the examined blood and what does it testify?
