<prompt> This test is used as a screening tool for?Hereditary spherocytosisG6PDThalassemiaMegaloblastic anemia  <response>: Ref: Harsh Mohan Textbook of Pathology, 7th ed. pg. 292 and Wintrobes Hematology, 13th ed. pg. 610 The image shows performance of Naked eye single tube, osmotic fragility test. Notice that in control sample on right side, the fine print of newspaper can be acknowledged. However, in the left sided sample, osmotic fragility is reduced leading to turbidity, leading to opacification of sample and the fine print of the newspaper cannot be read. This test is a screening test for thalassemia following which high performance liquid chromatography is done. 