The DAT is most likely to be negative in ABO HDFN.

The DAT is most likely to be negative in ABO HDFN. It's possible that the washing done as part of the DAT may break the bonds between anti-A (or anti-B) and the newborn's poorly developed A (or B) antigens.

For which of the following antibodies is the DAT most likely to be negative when testing a newborn for possible HDFN?