29 Apr

Rh Factor

Between 1900 and 1940 a lot of research was performed to uncover the presence of other antigens in human red blood cells.  In 1940, Landsteiner and Wiener reported that rabbit sera containing antibodies against the red blood cells of rhesus monkey would agglutinate the red blood cells of 5% of white humans.  This antigen in humans which was first designated as the Rh factor, was found to exist as six antigens: C, c, D, d, E, and e.  Of these six antigens, the D factor is responsible for the Rh-positive condition and is found in 85% of Whites, 94% of Blacks, and 99% of Asians.  Typing blood for the rh factor can also be performed by both tube and slide methods but there are differences between the two techniques.  The red blood cells must not be diluted in saline because they will not agglutinate and the test must be performed at 37 C for the tube test and 45 C for the slide test. pauln