Hemophilia A:

In diagnosing Hemophilia, doctors first test for Hemophilia A. Doctors take a blood sample of the patient and use a centrifuge to separate the red blood cells and the plasma. Then the doctors take normal plasma and remove the factor 8 from it. The doctors then add the plasma of the patient to the normal plasma. If the patient does not have hemophilia, then the factor 8 will be present in his plasma. When a clotting reagent is added to the plasma, if the factor 8 is present, then protein clots will form from white blood cells. The clots will then sink to the bottom of the tube. If there is little or no factor 8, then the protein will clot slowly or not at all. If he does not have the factor 8 then he has Hemophilia A. The doctors can now tell if the patient has Hemophilia A.

Hemophilia B:

If the patient does not have Hemophilia A and has the factor 8, then the doctors must also test for Hemophilia B. This is the same style test as for Hemophilia A but it is testing a different factor. This time the doctors test factor 9 in the blood. They remove the factor 9 from normal plasma. Then they add the plasma of the patient to the normal plasma. A clotting reagent is added again to activate the clotting. As in last time, if no clotting occurs then he is a hemophiliac with Hemophilia B. If clotting occurs then he does not have Hemophilia B.

Severity:

Once it is determined that the patient has the disease, he is tested for the level of severity. This is done by comparing his DNA with regular DNA. If his DNA is a different size than regular DNA then he has a severe case because there is a large change in his DNA from regular DNA. The DNA is measured with a special machine. A geneticist adds two DNA strands to a special gel, one from the patient and one regular DNA. As the DNA goes through the gel's matrix, then it is separated by length, because the smaller DNA will go deeper without getting caught in the gel matrix. Once the DNA has gone down as much as it can, then the difference in depth can be measured. The greater the distance apart the two DNA strands are, the greater the change in the persons DNA. The greater change in his DNA, then he has a more severe case.
Finally, the patient's close female relatives can be tested to see if they are carriers. Their DNA is also put through the gel matrix. If their DNA strand is the same length as the patient's DNA strand then they are carriers of the severe disease