Patent ID: 7129056

Claim:
A method for detecting circulating target fetal blood cells in a sample of a pregnant female donor's blood, which target fetal cells express human leucocyte antigens (target HLA epitopes) that differ from the donor's unique HLA epitopes, said method comprising the steps of: a) providing a transparent container having a cavity containing an insert said container and insert combining to form a free volume between the insert and a wall or walls of the container; b) combining the blood sample with one or more target HLA epitope specific labeling agents so as to colorimetrically differentiate any individual target cells in the blood sample from other cells in the blood sample; c) placing the blood sample in the container and centrifuging the blood sample in the container so as to cause any individual target cells present in the blood sample to localize in said free volume in the container; d) examining the centrifuged blood sample for the presence or absence of any individual differentiated target cells found in situ in the free volume in the container; and e) said combining step being performed either before or after the blood sample is placed in the container.