In clinics 5 indexes of the blood is calculated: color index, average hemoglobin content in the erythrocyte, average concentration of hemoglobin in the erythrocyte, average erythrocyte volume, average diameter of erythrocyte. It is necessary to define color index in clinical analysis.
The value of this index shows relative hemoglobin content in every erythrocyte. Normally color index is 0,85 – 1,15. Increase or decrease of it testifies interruption of the erythrocytes saturation with hemoglobin.
a b c
Figure 6.5 - Nomogram is used for the calculation of color index: a – normal color index value;
b – hemoglobin content by Sali method (%);
c – number of erythrocytes (in 1 l of blood)
To calculate hemoglobin amount in % the following operations are performed. For example there is 14 g% of hemoglobin in blood:
16,7 g% - 100%
14 g% - x x = 14•100 / 16,7 = 84%
Objectives: to define and estimate relative hemoglobin content in the erythrocyte.
Find the amount of erythrocytes in 1 mkl of blood and amount of hemoglobin, calculate color index (CI).
If the amount of hemoglobin is in g/l, then CI is calculated using a formula:
CI = (number of Hb (g/l)•3): (first 3 digits of the erythrocytes amount)
For example, if hemoglobin amount is 140 g/l, erythrocytes – 4,2 • 1012 (4 200 000 000 000), then CI = (140 • 3) : 420 = 1
Recommendations for writing down the results:
Calculate the color index using data from previous practical works.
Answer following questions in conclusion:
What is the degree of erythrocyte saturation with hemoglobin and what does it testify?
