N-Terminal end of albumin binds cobalt ions at physiological conditions. However, in the presence of oxidative stress, the binding capacity decreases and the level changes in various disorders. Conventionally used ischemia modified albumin (IMA) measurement method has severe defects. In this study, it is aimed to develop an authentic new generation IMA measurement method which can be used manually also fully automatically.
Assay has three stages. At the first stage, serum apotransferrines were completely saturated with ferric ions. In the second step, cobalt ions were added to the sample for the binding by albumin. In the third step, the remaining cobalt ions were bound to new chromogen. The assay was calibrated directly using a new calibrator and the results were given as serum IMA levels and also mole bound cobalt atom per one mole albumin molecule.
It has been demonstrated that original IMA measurement method has been effected from apotransferrin and pH factors. In the new assay, these interferences were completely removed. In the conventional method, the pH value of the reaction medium was unstabilized and in the new assay the pH of the reaction medium was stabilized using a new buffer solution. In the conventional method, the results are given as absorbance in the form of AU, and the results are given as SI in the new method.
New generation IMA assay, which has different measurement principle, reagents, chromogen and calibration, has high analytical performance characteristics and it can be used automatically and maually.
Key words: ischemia modified albumin, IMA
*Granted by TUBİTAK (117S455)