Which of the following test is used to estimate the amount of fetal maternal hemorrhage:

KLEIHAUER BETKE TEST or ACID ELUTION TEST done to measure the amount of feto maternal hemorrhage usually in an Rh negative mother to calculate the dose of anti D required This method is based on the fact that an acid solution (citric acid phosphate buffer, pH 3.5) elutes the adult but not the fetal hemoglobin from the red cells; can detect as little as 0.2 ml of fetal blood diluted in 5 L of maternal blood. More accurate tests are immunofluorescence and flow cytometry. Schiller test:- Schiller's iodine solution is applied to the uterine cervix under direct vision. Normal mucosa contains glycogen and stains brown, whereas abnormal areas, such as early CIN, do not take up the stain and appear white/yellow. Liley's spectrophotometer: Spectrophotometric analysis of amniotic fluid at optical density difference at 450 nm wavelength to see detion bulge in Rh hemolytic disease.