The strength of osmotic fragility test (OFT) in diagosis of microlcytic hypochromia

Baekgrouund & Diagnosis of microcytic hgpochromia is rutinely done using automatied equipment cell counter which is expensive and requaires expert. Personal OFT can be used for this globular defect. The aim of this study is to determine the best NaCL con centration in OFT, the experiments were done at fajer lab in 2001. 696 Random patients were examined simultaneouly for RBV indices by cell counter &method of onetube OFT. In this test. one drop (0.05 m1) of whole blood with 5 m1 of NaCl % 0.4 were mixed for 10 minutes, and after centrifuging. Supernatal for hemolysis. 382 patients with mcv> 80 had hemolysis. 228 patients with 74< mev <79 had hemolysis. 75 individuals with mcv<75 have no hemolysis and 5 with mcv>80 and 6 with 74. one tube OFT is very Sensetive for sereening of microcytic hypochromia but it is not practical for differential diagnosis of iron deficieney anenaia from minor thlassemia