This is National Blood Donor Month, and while you can do a lot of good by donating blood, you can also learn a little bit about yourself in the process.

Often after your donation is processed, you’ll get a message saying how much blood you gave, what it might be used for, and your blood type.

It was only in 1900 and 1901 that Austrian scientist Karl Landsteiner discovered that different people had different types of molecules on the surface of their red blood cells, known as antigens, as well as antibodies in the blood plasma.

The combination of antigens and antibodies help determine your blood type, and tell health care providers which types of blood are safe to use if you need extra.

Giving someone the wrong blood type could cause blood to clot up as part of an immune response, and you don’t want that to happen.

There’s type O blood, the most common type, and very useful, since in most cases people with the other blood types can receive it.

There’s also type A, type B, and type AB, which has both A and B antigens and can safely receive most of the other blood types.

These types can also have a type of antigen that’s known as positive or negative, so eight blood types cover almost everybody.

There are 36 other known blood types, many of them extremely rare.

Donation groups love it when a person with a rare blood type is willing to give regularly.

Maybe the rarest type is known as Rhnull, nicknamed “golden blood.”

It was first identified in 1961, and since then it’s only been found in 43 people.

It’s believed to be the blood type for one in six million people.

Rhnull is called “golden” not because it’s rare, but because it’s believed to be a type of blood that anyone with any of the dozens of rare blood types can use if they need it, without concerns that it might set off an immune response.

Fortunately nine of the 43 people known to have Rhnull blood have become donors.

If you’ve never given blood before, who knows… maybe yours is golden too.

Today in 1978, a very strange situation at the NFC Championship Game in Dallas.

A man in the stands dressed as a snowman bumped into a vendor selling hot chocolate, and the flaming can of Sterno set the snowman on fire!

He did get burned but was eventually ok.

‘Golden blood’ – only 43 people in the world have this rare blood type (Jerusalem Post)

Landry, Cowboy Coach, Enjoys Day at Movies (New York Times)

Our Patreon backers are as good as gold

Photo by Canadian Blood Services via Flickr/Creative Commons