Gynaecology & Obstetrics The Kleihauer Betke test for detecting foetal erythrocytes is based on the fact that A Adult erythrocytes are larger than those of foetus B HbA has higher oxygen affinity than HbF C HbF is more resistant acid elution than HbA D HbA takes up erythrosin stain less than HbF 💡 Explanation The Kleihauer Betke test for detecting foetal erythrocytes is based on the fact that ✓ Correct Answer: C. HbF is more resistant acid elution than HbA