what is the difference between rh negative and rh null?
The Rh blood group consists of several antigens - Rh(D), or D being the most important. O negative red blood cells lack the A and B antigens (hence, group O) and also the Rh(D) antigen. Rh null blood lacks all the antigens in the Rh group, such as D, C, c, E, e and others.