Test used to differentiate maternal and fetal blood is-
Ans. is 'a' i.e., APT test * The Apt test is a medical test used to differentiate maternal and fetal blood.* Leonard Apt, an American pediatric ophthalmologist, first developed this. It was then modified to distinguish fetal hemoglobin from maternal hemoglobin in blood samples from any source.* The Apt test may be used in cases of vaginal bleeding late during pregnancy (in cases of APH) to determine if the bleeding is from the mother or the fetus.* A positive test would indicate that blood is of fetal origin, and could be due to vasa previa. A negative test indicates that the blood is of maternal origin. In practice, the Apt test is almost never done when there is bleeding PV and a suspicion of vasa previa, because the time to fetal collapse with bleeding from vasa previa is often very short.* The test is based on the differences in the chemical properties between maternal and fetal hemoglobin. Adult hemoglobin is susceptible to alkaline denaturation whereas the fetal hemoglobin is resistant to it. The blood specimen is exposed to sodium hydroxide (NaOH) which will denature the adult hemoglobin but not the fetal hemoglobin. Under the microscope, the fetal hemoglobin will appear as a pinkish color while the adult hemoglobin will appear as a yellow-brownish color.* Other uses of APT test: If the newborn has blood in vomiting, or stools, or active bleeding from the nasogastric tube; a positive Apt test would mean that the bleeding is from the neonate. A negative Apt test would indicate that the blood is of maternal origin, suggesting that the neonate swallowed or aspirated maternal blood, either during delivery or during breastfeeding (e.g. from breast fissures).* The Kleihauer- Betke (KB) test, is a blood test used to measure the amount of fetal hemoglobin transferred from a fetus to a mothers bloodstream (to quantify the fetomaternal hemorrhage). It is performed on Rh negative mothers to help calculate the dose of ANTI-D injection.
APT test
Osmotic fragility test
Bubblin test
Kleihauer-Betke test
Miscellaneous (Gynae)