Question: how do you test blood?

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  1. Again I am not a doctor or a hematologist (see link 1) below) but I imagine Elise, and I suspect Janette, can you give you a full description of some of the more common tests that are done in pathology labs these days. I know as I am getting older I seem to have more and more of them being done …



  2. It depends on what you need to know! Our blood is made up of a lot of different components: white blood cells, red blood cells, proteins and fluids ( and all of them can be tested. You can get a lot of information from blood including DNA, and a blood sample can tell a lot about a person including if they are ill and even who they are (using the DNA found in white blood cells). The method and equipment we use for testing blood is different depending on what we want to know.

    The most commonly used test is to type blood. Blood typing refers to determining what markers (known as antigens) that sit on the outside of all your red blood cells. These markers are inherited from your parents. Blood types differ from person to person, and there are many different types of markers, but the most important are the one is based on an a particular marker and is typed as A, B, AB, or O.

    Blood typing is important, as if you mix two different blood types together a pretty bad reaction occurs – the blood clumps (agglutinates) and toxic reactions can take place. If you put the wrong blood type into a person it can kill them! The blood group O however is a special blood type, as it will not cause a reaction, so it is known as a ‘universal’ blood type, meaning that it can be given to people with other blood types without harming them.

    The most important application of this is when someone needs a blood transfusion (usually after an accident when they’ve lost a lot of blood), so blood banks (like the Red Cross) do a lot of testing to make sure the blood typing is correct, and the right blood is matched to a patient that has the same blood type.

    Here’s more information about blood types:
    And there’s even a game you can play about typing blood!:


  3. Janette has given a really great answer but I wanted to share this really cool new blood test that was invested by some Australian scientists and inspired by Harry Potter. They imprinted some special paper with a the chemicals that are used in blood typing, so that when the blood is spotted onto the paper, a symbol is revealed showing which type the blood is. Apparently they were inspired by Tom Riddle’s diary in Harry Potter and the Chamber of Secrets, and liked the idea of asking some paper a question and having it reveal the answer. A picture and more information can be found at the link below.


  4. The informaiton we can gain from blood tests is basically limitless, so long as the blood is collected properly. That is, sometimes we need it to be clotted (clumped) after collection and other times we need it to remain liquid. If we need it to remain in liquid form without any clumps, which we do for many blood tests than we need to add an anticoagulant. There are lots of different types of these but they act by blocking things like calcium in the blood, which stops the clumping proteins from being formed (check the section on anticoagulants outside the body As Janette has explained, there are many componensts in blood and each is useful for a differnt set of tests. The following web link outlines the tests that can be performed in a pathology lab on blood and other body fluids for all types of illnesses.

    The next link covers some basic information about the most common blood tests.


  5. No my area, but looking at whether the blood has all the right ingredients would be a start.