I have recently been learning about DNA testing and such, and I know there are four basic blood groups (A, B, AB and O) but can anyone explain why some people, such as myself, can be positive or negative? I am B negative and just wonder what the negative means?

bronagh96

I do know alot about DNA but i don't know what B-means sorry. You know that everyone in the universe has different DNA only identical twins have the same DNA, so it might have to do with something like that. Here i found this on a website, it might help you find out- "The aim of the present work is to characterize by computer simulation the free-energy difference between B- and Z-DNA in saline solutions. We use a new scheme to rigorously calculate the electrostatic contribution and we use it to test the theoretical predictions for a so-called `empty' DNA model (a set of charged hard spheres placed at the phosphate positions). The ions are considered as charged spheres in a continuum medium of dielectric constant equal to that of water. Also, we investigate the total free-energy difference for three different models differing exclusively in the degree of definition of the molecular shape. The comparison against experimental data shows that a precise shape is not required to give acceptable results. Finally, we use a simple grooved primitive model to study the effect of the ionic size and the ionic charges." Apr 02 05, 5:23 PM

kevinatilusa

The minus refers to the absence in your blood cells of the Rhesus Factor, or "Rh factor". I think effectively what it means is that you shouldn't receive blood transfusions from people who have the factor in your blood, as you may develop antibodies against it (similar to the effects of your receiving type A blood) Apr 02 05, 6:02 PM

lothruin

In particular, it refers to a protein which may or may not be present in the blood. People who are RH - (such as yourself), lack the protein. RH + have the protein. In connection with this protein are antibodies. People who are RH - can develop antibodies against the proteins in RH + blood, causing it to clump in the blood stream. Obviously, that is not good. This is why an RH - person should not receive RH + blood during transfusions, and also why there are problems if the RH factors between mother and fetus are different. This is also why the "universal donor" and "universal recipient" blood types specify RH factor as well as blood type. O- is the universal donor because persons who are RH + CAN safely receive RH - blood. The universal recipient is AB+. Apr 03 05, 9:00 AM

kbaby2309

thanks for your help everyone! it is starting to make a bit more sense now! Apr 03 05, 9:28 AM

Flynn_17

I'm thoroughly screwed when it comes to getting blood, being AB-. There are also the blood groups E and H, but those are rare. Apr 03 05, 1:44 PM

Baloo55th

On a slight irrelevancy, do blood groups matter to vampires or is it only transfusions that could cause problems? Apr 03 05, 1:52 PM

gmackematix

I have good news for you Flynn. The AB blood group has A and B antigens so does not reject blood from any other group in the ABO system. Clearly, Galton and Simpson didn't realise this when they wrote Tony Hancock's famous "Blood Donor" episode. Apr 03 05, 5:33 PM