In Season 5, episode 3 of New Amsterdam (also here), a patient can't receive O negative blood.

I, being "O neg", always thought that absolutely everyone, without exception could get O negative blood.

Are there any exceptions, even if incredibly rare?

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    – Carey Gregory
    Commented Aug 26, 2023 at 2:41
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    And keep in mind that it's a TV series you're talking about. They could just be making stuff up.
    – Carey Gregory
    Commented Aug 26, 2023 at 2:42
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    @CareyGregory Yes, that's why I'm asking. Because I'm not going to take a TV drama at face value. Thank you for your input. Commented Aug 26, 2023 at 19:15
  • Just in case, compared to the TV Fanatic and Wikipedia, the review on Nerds & Beyond explicitly mentioned about the recipient being not able to receive O-negative blood because he has "a rare blood type".
    – Andrew T.
    Commented Aug 27, 2023 at 3:16

3 Answers 3


O negative blood doesn't have either the A or B antigen, and is also negative for the rhesus antigen. These are the most common antigens expressed on blood cells, and are responsible for most transfusion reactions, hence it can be given to the vast majority of people without harm.

There are several hundred other antigens that can be present. These are less common, and tend to cause less severe reactions, but can cause problems. Therefore it is possible for O negative blood to cause a transfusion reaction, and it is also possible for a particular unit of O neg to be tested and found not to be suitable for a particular patient. This will only apply to that unit (and others from the same donor) - there will be other units of O negative that are compatible, and there will not be a situation where a patient cannot receive O negative blood, provided the other antigens are screened for and matched.

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    This answer is correct, but (imo) doesn't quite answer the question directly (it does if one reads between the lines, i.e. "This will only apply to that unit..."). Commented Aug 26, 2023 at 16:02
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    @anongoodnurse I don't think one can get much more clear than "there will not be a situation where a patient cannot receive O negative blood".
    – NotThatGuy
    Commented Aug 28, 2023 at 12:48
  • @NotThatGuy - The quote is "...there will not be a situation where a patient cannot receive O negative blood, provided the other antigens are screened for and matched." When giving O- blood, it's usually an emergency (we don't give blood willy nilly; all blood is typed and cross matched otherwise.) Commented Aug 28, 2023 at 14:36
  • My biology textbook describe the reverse problem as also existing sometimes; the O- blood might carry enough anti-A or anti-B antigens to be disastrous. Usually it's not a real problem on a slow feed.
    – Joshua
    Commented Aug 29, 2023 at 4:36

The incident in that episode of television was mostly pure fantasy.

There are 35 blood type groups recognized by the International Society of Blood Transfusion, but for simplicity's sake, most people only really need to know about the two most important ones: ABO and the Rhesus D.

Although there are hundreds (?) of other antigens, O- blood is the universal donor, and there's no reason that someone cannot "ever" receive O- blood, unless they are Jehovah's Witnesses. As all blood types will also contain other antigens, and there are none specific to O that would make it truly problematic*, not getting it in an emergency could result in death. A transfusion reaction not involving the A, B, or most common Rh types can occur with any blood type at all, none specific to O-. If the patient can never receive O- blood, they could never receive any other blood, either.

There are blood types that are very rare and very valuable for that reason; one is called -D-.

The Rh blood group system is the most polymorphic of the human blood groups, consisting of at least 45 independent antigens and, next to ABO, is the most clinically significant in transfusion medicine.

The most common Rh antigens are D, C,c, and E,e. Rh- means there is no D antigen on blood cells. One (or both) of the other two are present, and they are not specific to ABO type cells. One blood group, called -D- (or D--) has no D,C/c, or E/e antigens. There are only 110 such donors in the world on the International Blood Group Reference Laboratory database, of which 80% are in Japan.

Yet it's not the rarest blood type. Rhnull is the rarest, as it expresses none of the 60+ Rh antigens due to a mutation in the ability to express Rh at all. There are only a handful (is 8 a handful? Is 9 pushing it?) of registered Rhnull donors, and only ~40 individuals identified worldwide. They have been called the Golden Donors, and theirs the Golden Blood.

So, I cannot imagine a scenario where a person cannot receive "only" O- blood under any circumstance.

In real life, in a life threatening emergency, O- blood ("washed" if it is available), is given. If the patient is visibly hemorrhaging out in front of the medical team, they don't care if the first unit or two is washed or not, O- is given while the patient's blood is being typed and screened. In non-emergent cases, blood is typed and crossmatched, which takes longer.

So, it's possible that some individuals need a rare blood type, but it's not based on the combination of "O-".

*There is only one that I could find in the literature, which involves a donor who has been exposed to Norovirus, and a recipient who has also been so exposed. I don't know the severity of the reaction. But it has nothing to do with the Rh factor.)


Bombay phenotype

hh or the Bombay blood group, is a rare blood type. This blood phenotype was first discovered in Bombay by Dr. Y. M. Bhende in 1952. It is mostly found in the Indian sub-continent (India, Bangladesh, Pakistan) and Iran.

...people who have Bombay phenotype can donate red blood cells to any member of the ABO blood group system (unless some other blood factor gene, such as Rh, is incompatible), but they cannot receive blood from any member of the ABO blood group system (which always contains one or more of A, B or H antigens), but only from other people who have Bombay phenotype.

One rarely sees people who carry Bombay blood group so the issue is rarely discussed, esp. outside of India where this gene is hardly ever seen.

  • Now I'm wondering if they can receive blood from Rhnull.
    – Clockwork
    Commented Aug 28, 2023 at 11:22
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    @Clockwork this is a different "compatibility space". hh-blood people can be Rh-whatever just like anyone else.
    – fraxinus
    Commented Aug 28, 2023 at 12:29
  • Interesting! I must have encountered this in med school, but certainly not since. Thanks! Commented Aug 28, 2023 at 14:46
  • Wow! I'm UK trained and have never come across this- thank you for the update. Easy to get lazy in thinking of type-O as having no antigens, rather than it simply lacking A and B.
    – Michael
    Commented Aug 28, 2023 at 15:34

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