Differential effect of detergents on the alkaline denaturation of haemoglobin in maternal and fetal blood, with particular reference to Triton X-100

In this investigation, the alkaline denaturation of haemoglobin in the blood of pregnant women and in cord blood obtained from newborn infants was followed by measuring the increase in absorbance at 375 nm. As expected, in the absence of detergent, the haemoglobin of cord blood was much more resistant to alkaline denaturation than that of maternal blood. However, in the presence of Triton X-100, a non-ionic detergent, the sensitivity of fetal haemoglobin to alkali was comparable to that of adult haemoglobin. Similar results were obtained using the non-ionic detergents, Brij-35, Tween 80 and Nonidet P40, but the anionic detergent, sodium deoxycholate, was apparently without effect. These findings form the basis of a rapid and sensitive method for discriminating between maternal and fetal blood in biological specimens.