[A direct micromethod for transferrin level determination in human serum (author's transl)].

All the methods of quantitative estimation of transferrin concentration applied until recently have consisted in calculating the amount of this protein through the amount of iron bound in the blood serum. For this purpose the total iron binding capacity of serum (TIBC) has to be determined and then transferrin concentration is calculated. The calculation is based on the fact found by Ehrenberg and Laurell (1955) that two atoms of trivalent iron are selectively bound with one molecule of transferrin. The disadvantage of this method consists mainly in the necessity to carry out the measurement twice in every serum sample and in the large amount of material necessary for the analyses: this is a great inconvenience for pediatric clinics. The single-radial diffusion method in agar-gel was evaluated to be very advantageous for quantitative estimation of transferrin because of its simple technique and reaction specifity. The quantitative estimation is possible by the pilot calibration curve that represents the relationship of the diameter of a given circle and transferrin concentration. The quantity of material necessary for analysis amounts to not more than 5 mul of serum. Specific antitransferrin serum has to be imported and this seems to be the only reason why the said technique has not been used in Poland so far. The sera and vaccine laboratories in Warsaw have recently started to produce this antiserum and pure human transferrin. This has stimulated us to work out the single-radial diffusion method in agar based on Polish antiserum and Polish standard. The quality of the Polish specific rabbit antitransferrin serum and Polish pure human transferrin was tested by the immunoelectrophoretic method. The above findings provide the evidence that the Polish reagents are as good as those of the Behringwerke. Single-radial diffusion in agar gel should be carried out under the following conditions. 1) reaction temperature: 20-22degreesC 2) reaction time 24 hours 3) optimum concentration of antitransferrin serum in agar is 1:5.2. The error of the immunochemical method was determined experimentally and was found to be 9.05%. The results obtained with Polish and Behringwerke reagents were compared and were very similar.