<s>[INST] context: Apt test Both Apt test and Kleihaur-betke test can be used to detect the presence of fetal blood within a sample. Apt Test -Is used to detect the presence or absence of fetal blood (qualitative) in a vaginal discharge to rule out vasa pre late in pregnancy or to detect the origin of a neonatal bloody, vomiting whether it's a genuine upper GI hemorrhage/hemoptysis or simply a swallowed maternal blood during delivery or from cracked nipple. Kleihauer-Betke Test -The sample is maternal peripheral smear and is used to see how much of fetal blood (quantitative) has been transfused into the maternal serum in order to assess the risk of isoimmunization and then the risk of hemolytic disease of the newborn. Both of them relies on the fact that HbF is resistant to alkali (Apt) and acids (Kleihauer) and so the HbA containing RBCs (maternal) will be hemolyzed but not the fetal RBCs as they contain the HbF. In simple words When fetal blood needs to be differentiated from adult (maternal) blood Apt test is used --> (qualitative estimation). When the amount of fetal bleeding needs to estimated Kleihauer Betke test is used --4 (quantitative estimation). The question has asked about the test used to differentiate between maternal and *fetal blood therefore the answer should he Apt test. Apt test Kleihaur Betke test Source of sample Maternal or neonatal Maternal How it works Adding 1% NaOH destroys adult HbA but not fetal HbF Adding acid destroys adult HbA but not fetal HbF Assessement type Qualitative Quantitative Result Positive means blood is of fetal origin Repoed in estimated 'inr s of fetal blood [/INST] question: Which test differentiate maternal and fetal blood CellaEUR' | options: A: Apt test B: Kleihauer-Betke test C: Bubblin test D: Osmotic fragility test | answer: A </s>