What’s thick, red, and can save lives?
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It’s blood of course. And recently on June 14, the world celebrated people who give theirs away. It was World Blood Donor Day.
Recently, I had the pleasure of hosting groups of local high school students in our labs as part of our annual HSC Booster days. One of the things that we talked about was how we can determine what type of blood people have.
Most adults probably know their blood type – but what do those As, Bs, ABs and Os actually mean?
No blood type is better or worse than any other – although there is plenty of pseudoscience that would have you believe otherwise.
Our blood type is determined by our DNA – it’s something that we inherit from our parents. We have a gene, called the ABO gene, which makes proteins that sit on the surface of our red blood cells.
Different people have different versions of this gene. Some people have a version of the gene that produces a type A protein – and so have type A blood. Some people produce a different form of the protein, called the type B protein, giving them type B blood.
Because we all have two copies of the gene it’s also possible to have both of these forms and have type AB blood.
And some people have yet another form of the gene which does not produce any protein, resulting in type O blood.
There is a second gene, called the rhesus gene, which determines if our blood type is positive or negative. We can also have different versions of this gene.
If we have the version that makes a protein on our cells, then our blood type will be positive. If we don’t, then our blood type will be negative.
Together these two genes give us a total of eight different blood types: A+, A-, B+, B-, AB+, AB-, O+ and O-.
Which blood type is best?
No blood type is better or worse than any other – although there is plenty of pseudoscience that would have you believe otherwise.
Have you ever heard that you should follow a specific diet based on your blood type? Or that people with certain blood types are more intelligent? There’s no actual scientific evidence for any of these – your blood type doesn’t really matter much.
Unless, of course, you need a blood transfusion.
There is some pretty serious science behind blood transfusions. It’s essential that donated blood is carefully matched to a recipient before transfusion, or there can be dangerous consequences.
Getting it right
This is because each of us produces antibodies that will recognise and react with the proteins that we don’t have on our cells.
For example I have type O blood – so I will produce antibodies that will recognise both the A and B proteins. If I am given type A, B or AB blood then my antibodies will react with those blood cells, and destroy them. And that can be fatal.
So when it comes to blood donations, blood types are really important.
If you want to find out your blood type there’s a really simple way. You can just pop along to a blood donor centre and give blood.
To find out more, visit www.donateblood.com.au
